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rev 1.5 - june 2002 1/94 this is preliminary information on a new product foreseen to be developed. details are subject to change without notice. target specification ST52F500/f503/f504 8-bit intelligent controller unit (icu) two timer/pwms, i 2 c, spi ? memories n up to 8 kbytes single voltage flash memory n up to 512 bytes of ram n up to 4 kbytes data eeprom n in situ programming in flash devices (isp) n single byte and page modes and in application programming for writing data in flash memory n readout protection and flexible write protection core n register file based architecture n 107 basic instructions n hardware multiplication and division n decision processor for the implementation of fuzzy logic algorithms n deep system and user stacks clock and power supply n up to 24 mhz clock frequency n programmable oscillator modes: 10 mhz internal oscillator external clock/ oscillator external rc oscillator n power-on reset (por) n programmable low voltage detector (plvd) with 3 configurable thresholds n power saving features interrupts n 8 interrupt vectors with one sw trap n non-maskable interrupt (nmi) n two port interrupts with up to 16 sources i/o ports n from 10 up to 22 i/o pins configurable in pull- up, push-pull, weak pull-up, open-drain and high-impedance n high current sink/source in all pins peripherals n 2 programmable 16 bit timer/pwms with internal 16-bit prescaler featuring: pwm output input capture output compare pulse generator mode n watchdog timer n i 2 c peripheral with master and slave mode n 3-wire spi peripheral supporting single master and multi master spi modes development tools n high level software tools n `c' compiler n emulator n low cost programmer n gang programmer ST52F500/f503/f504
ST52F500/f503/f504 2/94
3/94 table of contents ST52F500/f503/f504 1 general description ......................................... 7 1.1 introduction . . . . . . . . . . .........................................................7 1.2 functional description . . ........................ ................................8 1.2.1 memory programming mode . . . . . . . . . . . . . . .................................. 8 1.2.2 working mode. ........................................................... 8 1.3 pin description . . . . . . . ........................................................14 2 internal architecture. . . . . . . . . . . . . ......................... 15 2.1 control unit and data processing unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ......15 2.1.1 program counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................... 16 2.1.2 flags. . . . . . . . . . . ....................................................... 16 2.2 arithmetic logic unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...............................17 2.3 register description . . . . ........................ ...............................18 3 addressing spaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........ 19 3.1 memory interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...............................19 3.2 register file . . . . . . . . . ........................................................19 3.3 program/data memory . . . . . . . . . . . . . . . . . . . . . . . ..................................19 3.4 system and user stacks ........................................................21 3.5 input registers . . . . . . . . ........................ ...............................22 3.6 output registers . . . . . . ........................................................22 3.7 configuration registers & option bytes . . . . . . . ...................... ...............22 4 memory programming . . . . . . . . . . . . . .......................... 28 4.1 program/data memory organization . . . . . . . . . . . . ..................................28 4.2 memory programming . . . . . . . . . . . . . . . . . . . ......................................29 4.2.1 programming mode start . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................... 29 4.2.2 fast programming procedure. . . . . . . . . . . . . . . . . .............................. 30 4.2.3 random data writing. . . . . . . . . . . . . . . . . . . . . ................................. 30 4.2.4 option bytes programming. . . . . . . . . . . . . . . . ................................. 31 4.3 memory verify. ...............................................................32 4.3.1 fast read procedure . . . ................................................... 32 4.3.2 random data reading . . ................................................... 33 4.4 memory lock . ........................................ .......................33 4.5 id code. . . . . . ...............................................................34 4.6 error cases . ......................... ........................................34 4.7 in-situ programming (isp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................35 4.8 in-application programming (iap) . . . . . . . . . . ......................................35 4.8.1 single byte write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................... 35 4.8.2 block write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............................. 35 4.8.3 memory corruption prevention. . . . . . . . . . . . . . . . . . . . . . . ....................... 35 4.8.4 option bytes . . . . . . . . . . . . . . . . . . . . . . . ..................................... 36 4.8.5 input register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............................. 36 table of contents
ST52F500/f503/f504 4/94 5 interrupts . . . . . . . . . . . . . . . . . . ................................ 37 5.1 interrupt processing . . . ........................................................37 5.2 global interrupt request enabling . . . . . . . . . . ......................................37 5.3 interrupt sources . . . . . ........................................................38 5.4 interrupt maskability and priority levels . . . . . . . ...................... ...............38 5.5 interrupt reset . . . . . . ........................................................38 5.6 register description . . . . ........................ ...............................39 6 clock, reset & power saving modes . ....................... 41 6.1 clock. ......................................................................41 6.2 reset. ......................................................................42 6.2.1 external reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............................. 42 6.2.2 reset procedures. . . . . . . . . . . . . ........................................... 42 6.3 programmable low voltage detector. . . . . . . . ......................................43 6.4 power saving modes . . ........................................................43 6.4.1 wait mode. . . . . . . . . . . . . . . . . . . . . . . . . . . ................................... 43 6.4.2 halt mode . . . . . . . . . . . . .................................... .............. 43 6.5 register description . . . . ........................ ...............................45 6.5.1 configuration register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6.5.2 option bytes . . . . . . . . . . . . . . . . . . . . . . . ..................................... 45 7 i/o ports . . . . . . . . . . . . . . ...................................... 47 7.1 introduction . . . . . . . . . . ........................................................47 7.2 input mode . ......................... ........................................47 7.3 output mode . . ...............................................................47 7.4 interrupt mode. ...............................................................47 7.5 alternate functions. . . . . ........................ ...............................48 7.6 register description . . . . ........................ ...............................48 7.6.1 configuration registers . . . . . . . . . . . . . . . . . . ................................. 49 7.6.2 input registers .......................................................... 51 7.6.3 output registers. . ....................................................... 51 8 fuzzy computation (dp). . . . . . ................................ 53 8.1 fuzzy inference . . . .................................... .......................53 8.2 fuzzyfication phase . . . ........................................................53 8.3 inference phase . . . .................................... .......................53 8.4 defuzzyfication ...............................................................54 8.5 input membership function . . . . . . . . . ............................................54 8.6 output singleton . . . . . . . ........................ ...............................55 8.7 fuzzy rules . . ...............................................................55 9 instruction set ............................................. 57 9.1 addressing modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....57 9.2 instruction types. . . . . . ........................................................57
ST52F500/f503/f504 5/94 10 watchdog timer. . . ......................................... 62 10.1 functional description . . . . . . . . . . . . . . . . . . ......................................62 10.2 register description . . ........................................................62 11 pwm/timers . . . . . . . . . . ....................................... 64 11.1 introduction . . ...............................................................64 11.2 timer mode. . . . . . . . . . ........................ ...............................64 11.3 pwm mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..................................66 11.3.1 simultaneous start . . . . . . . . . . . . . . . . . . . . . . . . .............................. 67 11.4 timer interrupts. . . . . . . ........................ ...............................67 11.5 pwm/timer 0 register description. . . . . . . . . . . . . ..................................67 11.5.1 pwm/timer 0 configuration registers . . . . . . . . . .............................. 67 11.5.2 pwm/timer 0 input registers. . . . . . . . . ..................................... 68 11.5.3 pwm/timer 0 output registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... 69 11.6 pwm/timer 1 register description. . . . . . . . . . . . . ..................................70 11.6.1 pwm/timer 1 configuration registers . . . . . . . . . .............................. 70 11.6.2 pwm/timer 1 input registers. . . . . . . . . ..................................... 71 11.6.3 pwm/timer 1 output registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... 72 12 i2c bus interface (i2c) . . . . . . ................................ 73 12.1 introduction . . ...............................................................73 12.2 main features. . . . . . . . . . . . . . . . ...............................................73 12.3 general description . . . . . . . . . . . . . . . . . . . . . . . . . . . ...............................73 12.3.1 mode selection. . . . . . . . . . . . . . . . . . . . . . . . ................................. 73 12.3.2 communication flow . . . . . . .............................................. 73 12.3.3 sda/scl line control . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................... 74 12.4 functional description . . . . . . . . . . . . . . . . . . ......................................74 12.4.1 slave mode. . . . . . ........................ .............................. 74 12.4.2 master mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............................. 75 12.5 register description . . ........................................................79 12.5.1 i2c interface configuration registers ................................... ..... 79 12.5.2 i2c interface input registers . . . . . . . ....................................... 80 12.5.3 i2c interface output registers . . . . . . . . . . . . . . . . . . . . . . ....................... 82 13 serial peripheral interface (spi) . . . ....................... 83 13.1 introduction . . ...............................................................83 13.2 main features. . . . . . . . . . . . . . . . ...............................................83 13.3 general description. . . . . . . . . . . . . . . . . . . . . . . . . ..................................83 13.4 functional description . . . . . . . . . . . . . . . . . . ......................................83 13.4.1 master configuration . . .................................... .............. 83 13.4.2 slave configuration . . ................................................... 85 13.4.3 data transfer format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................... 85 13.4.4 write collision error . . . . . . . . . . . . . . . . ..................................... 85 13.4.5 master mode fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....................... 86 13.4.6 overrun condition. . . . . . . . . . . . . . . . . . ..................................... 88
ST52F500/f503/f504 6/94 13.4.7 single master and multimaster configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... 88 13.4.8 interrupts. . . . . . . . . . . . . . . . . . . ........................................... 89 13.5 spi register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ......90 13.5.1 spi configuration registers . . . . . . . . . . . . . . . . . . . . . . . . . ...................... 90 13.5.2 spi input register. . . . ................................................... 91 13.5.3 spi output register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... 92
ST52F500/f503/f504 7/94 1 general description 1.1 introduction ST52F500/f503/f504 are devices of st five family of 8-bit intelligent controller units (icu), which can perform, both boolean and fuzzy algorithms in an efficient manner, in order to reach the best performances that the two methodologies allow. produced by stmicroelectronics using the reliable high performance cmos process for single voltage flash versions, ST52F500/f503/f504 include integrated on-chip peripherals that allow maximization of system reliability, and decreased system costs in order to minimize the number of external components. the flexible i/o configuration of ST52F500/f503/ f504 allow one to interface with a wide range of external devices (for example d/a converters or power control devices), and to communicate with the most common serial standards. ST52F500/f503/f504 pins are configurable. the user can set input or output signals on each single pin in 8 different modes, reducing the need for external components in order to supply a suitable interface with the port pins. a hardware multiplier and divider, together with a wide instruction set, allow the implementation of complex functions by using a single instruction. therefore, program memory utilization and computational speed is optimized. fuzzy logic dedicated structures in ST52F500/ f503/f504 icu's can be exploited to model complex system with high accuracy in a useful and simple manner. fuzzy expert systems for overall system management and fuzzy real time controls can be designed to increase performance at competitive costs. the linguistic approach characterizing fuzzy logic is based on a set of if-then rules, which describe the control behavior and on membership functions associated with input and output variables. up to 340 membership functions, with triangular and trapezoidal shapes, or singleton values are available to describe fuzzy variables. the timer/pwm peripheral allows one to manage power devices and timing signals, by implementing different operating modes and high frequency pwm (pulse width modulation) controls. input capture and output compare functions are available on the timers. the timer has a 16-bit programmable internal prescaler and a 16-bit counter, which can use internal or external start/stop signals and clock. an internal programmable watchdog is available to avoid loop errors and reset the icu. ST52F500/f503/f504 supply different peripherals to implement the most common serial communication protocols. i 2 c and spi peripherals allow the implementation of synchronous serial protocols. i 2 c peripherals can work both in master and slave mode. spi implements single and multi master modes using 3-wire. up to 8 interrupt vectors are available, which allow synchronization with peripherals and external devices. non-maskable interrupt and s/w trap are available. all interrupts have configurable priority levels and are maskable excluding the non-maskable interrupt, which has fixed top level priority. two versatile port interrupts are available for synchronization with external sources. the ST52F500/f503/f504 also include an on-chip power-on-reset (por), which provides an internal chip reset during power up situation and a programmable low voltage detector (plvd), which causes the icu to reset if the voltage source v dd dips below a threshold. three programmable thresholds are available, allowing to work with different supply voltages (from 2.4 to 5.5 v). in order to optimize energy consumption, two different power saving modes are available: wait mode and halt mode. internal oscillator at 10 mhz 1% is available. external clock, quartz oscillator or rc oscillator are also applicable. the device always starts with the internal oscillator, then it reads an option byte where the clock mode to be used is programmed. program memory addressing capability addresses up to 8 kbytes of memory location to store both program instructions and data. memory can be locked by the user in order to prevent external undesired operations. operations may be performed on data stored in ram, allowing direct combination of new inputs and feedback data. all ram bytes are used like register file. an additional ram bench is added to the program memory addressing space in order to allow the management of the system/user stacks and user data storage. ST52F500/f503/f504 supply the system stack and the user stack located in the additional ram bench. the user stack can be located anywhere in the additional ram by writing the top address in the configuration registers, in order to avoid overlap with other data. single voltage flash allows the user to reprogram the devices on-board by means of the in situ programming (isp) feature. it is possible to store in safe way up to 4k of data in the available eeprom
ST52F500/f503/f504 8/94 memory benches. permanent data, both in flash and eeprom can be managed by means of the in-application-programming (iap) feature. single byte and page write modes are supported. flexible write protection, of permanent data or program instructions, is also available. the instruction set composed of up to 107 instructions allows code compression and high speed in the program implementation. a powerful development environment consisting of a board and software tools allows an easy configuration and use of ST52F500/f503/f504. the visual five software tool allows the development and debugging of projects via a user- friendly graphical interface and optimization of generated microcode. third-party hardware emulators and `c' compiler are available to speed-up the application implementation and time-to-market. 1.2 functional description ST52F500/f503/f504 icu's can work in two modes according to the vpp signal levels: n memory programming mode n working mode during working mode vpp must be tied to vss. to enter the memory programming mode, the vpp pin must be tied to vdd. a reset signal must be applied to the device to switch from one mode to the other. 1.2.1 memory programming mode. the ST52F500/f503/f504 memory is loaded in the memory programming mode. all instructions and data are written inside the memory during this phase. the option bytes are loaded during this phase by using the programming tools. the option bytes can only be loaded in this phase and cannot be modified run-time. data and commands are transmitted by using the i 2 c protocol, implemented using the internal i 2 c peripheral. the in-situ programming protocol (isp) uses the following pins: n sda and scl for transmission n vpp for entering in the mode n reset for starting the protocol in a stable status n vdd and vss for the power supply. the internal clock is used in this phase. 1.2.2 working mode. the processor starts the working phase following the instructions, which have been previously loaded in the first locations of the memory. the first instruction must be a jump to the first program instruction, skipping the data (interrupt vectors, membership functions, user data) stored in the first memory page. ST52F500/f503/f504's internal structure includes two computational blocks, the control unit (cu) and the data processing unit (dpu), which performs boolean functions. the decision processor (dp) block cooperates with these blocks to perform fuzzy algorithms. the dp can manage up to 340 different membership functions for the antecedent part of fuzzy rules. the consequent terms of the rules are acrispo values (real numbers). the maximum number of rules that can be defined is limited by the dimensions of the standard algorithm implemented. the program/data memory is shared between fuzzy and standard algorithms. within this memory, the user data can be stored both in non volatile memory as well as in the ram locations. the control unit (cu) reads information and the status of the peripherals. arithmetic calculus can be performed on these values by using the internal cu and register file, which supports all computations. the peripheral inputs can be fuzzy and/or arithmetic output values contained in the register file or program/ data memory.
ST52F500/f503/f504 9/94 legend: table 1.1 ST52F500/f503/f504 devices summary device nvm ram eeprom timers adc comms i/o package ST52F500ympy 1/2/4/8 k flash 256/512 - 2x16-bit - i 2 c 10 dip/so 16 st52f50 0fmpy 1/2/4/8 k flash 256/512 - 2x16-bit - i 2 cspi 14 dip/so 20 ST52F500gmpy 1/2/4/8 k flash 256/512 - 2x16-bit - i 2 cspi 22 dip/so 28 st52f503ympy 1/2/4/8 k flash 256/512 128/256 2x16-bit - i 2 c 10 dip/so 16 st52f50 3fmpy 1/2/4/8 k flash 256/512 128/256 2x16-bit - i 2 cspi 14 dip/so 20 st52f503gmpy 1/2/4/8 k flash 256/512 128/256 2x16-bit - i 2 cspi 22 dip/so 28 st52f504ympy 4k flash 512 512/1024/ 2048/4096 2x16-bit - i 2 c 10 dip/so 16 st52f50 4fmpy 4k flash 512 512/1024/ 2048/4096 2x16-bit - i 2 cspi 14 dip/so 20 st52f504gmpy 4k flash 512 512/1024/ 2048/4096 2x16-bit - i 2 cspi 22 dip/so 28 note: devices with1-2k flash have 256 ram / 128 eeprom common features ST52F500/f503/f504 watchdog yes other features nmi, plvd, por temperature range from -40 to +85 operating supply 2.4 - 5.5 v cpu frequency from 1 to 24 mhz. sales code: st52tnnncmpy memory type (t): f=flash, t=otp, e=eprom subfamily (nnn): 500, 503, 504, 510, 513, 514, 520, 521, 530 pin count (c): y=16 pins, f=20 pins, g=28 pins, k=32/34 pins, j=42/44 pins memory size (m): 0=1 kb, 1=2 kb, 2=4 kb, 3=8 kb flash (st52x500 & st52x503) 0=512, 1=1024, 2=2048, 3=4096 bytes eeprom (st52x504) packages (p): b=pdip, d=cdip, m=pso, t=tqfp temperature (y): 0=+25, 1=0 +70, 3=-40 +125, 5=-10 +85, 6=-40 +85, 7=-40 +105
ST52F500/f503/f504 10/94 figure 1.1 ST52F500/f503/f504 block diagram port a timer/pwm 0 port c timer/pwm 1 i 2 c pa7:0 spi pc5:0 port b pb7:0 watchdog memory flash isp/iap data ram 256 bytes data eeprom core decision processor control unit register file 256 bytes input registers pc flags power supply & plvd power on reset oscillator vdd vpp vss oscin oscout reset alu & dpu memory interface
ST52F500/f503/f504 11/94 figure 1.2 ST52F500/f503/f504 so28/dip28 pin configuration figure 1.3 ST52F500/f503/f504 so20/dip20 pin configuration vdd oscout oscin vpp pb0/sck pb1/mosi pb2/miso pb3/ss pb4 pb5 pb6 pb7 pc0 pc1 vss reset pa0/scl pa1/sda pa2/t1out pa3/tres pa4/tstrt pa5/tclk pa6/t0out pa7/int pc5 pc4 pc3 pc2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 so28 pdip28 vss reset pa0/scl pa1/sda pa2/t1out pa3/tres pa4/tstrt pa5/tclk pa6/t0out pa7/int pc5 pc4 pc3 pc2 vdd oscout oscin vpp pb0/sck pb1/mosi pb2/miso pb3/ss pb4 pb5 pb6 pb7 pc0 pc1 vdd oscout oscin vpp pb0/sck pb1/mosi pb2/miso pb3/ss pb4 pb5 vss reset pa0/scl pa1/sda pa2/t1out pa3/tres pa4/tstrt pa5/tclk pa6/t0out pa7/int 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 vdd oscout oscin vpp pb0/sck pb1/mosi pb2/miso pb3/ss pb4 pb5 vss reset pa0/scl pa1/sda pa2/t1out pa3/tres pa4/tstrt pa5/tclk pa6/t0out pa7/int 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 so20 pdip20
ST52F500/f503/f504 12/94 figure 1.4 ST52F500/f503/f504 so16/dip16 pin configuration vdd oscout oscin vpp pb0 pb1 pa7/int pa6/t0out vss reset pa0/scl pa1/sda pa2/t1out pa3/tres pa4/tstrt pa5/tclk 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 vdd oscout oscin vpp pb0 pb1 pa7/int pa6/t0out vss reset pa0/scl pa1/sda pa2/t1out pa3/tres pa4/tstrt pa5/tclk 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 so16 pdip16
ST52F500/f503/f504 13/94 table 1.2 ST52F500/f503/f504 pin list so28 dip28 so20 dip20 so16 dip16 name programming phase working phase 1 1 1 vdd digital power supply digital power supply 2 2 2 oscout oscillator output 3 3 3 oscin oscillator input 4 4 4 vpp programming mode selector programming mode selector 5 5 5 pb0/sck digital i/o, spi serial clock 6 6 6 pb1/mosi digital i/o, spi master out slave in 7 7 - pb2/miso digital i/o, spi master in slave out 8 8 - pb3/ss digital i/o, spi slave select 9 9 - pb4 digital i/o 10 10 - pb5 digital i/o 11 - - pb6 digital i/o 12 - - pb7 digital i/o 13 - - pc0 digital i/o 14 - - pc1 digital i/o 15 - - pc2 digital i/o 16 - - pc3 digital i/o 17 - - pc4 digital i/o 18 - - pc5 digital i/o 19 11 7 pa7/int digital i/o, non maskable interrupt 20 12 8 pa6/t0out digital i/o, timer/pwm 0 output 21 13 9 pa5/tclk digital i/o, timer/pwm 0 clock 22 14 10 pa4/tstrt digital i/o, timer/pwm 0 start/stop 23 15 11 pa3/tres digital i/o, timer/pwm 0 reset 24 16 12 pa2/t1out digital i/o, timer/pwm 1 output 25 17 13 pa1/sda serial data i/o digital i/o, i 2 c serial data i/o 26 18 14 pa0/scl serial clock digital i/o, i 2 c serial clock 27 19 15 reset general reset general reset 28 20 16 vss digital ground digital ground
ST52F500/f503/f504 14/94 1.3 pin description ST52F500/f503/f504 pins can be set in digital input mode, digital output mode, interrupt mode or in alternate functions. pin configuration is achieved by means of the configuration registers. the functions of the ST52F500/f503/f504 pins are described below: v dd. main power supply voltage. v ss . digital circuit ground. v pp . programming/working mode selector. during the programming phase v pp must be set to v dd . in working phase v pp must be equal to v ss . oscin and oscout. these pins are internally connected to the on-chip oscillator circuit. a quartz crystal or a ceramic resonator can be connected between these two pins in order to allow correct use of ST52F500/f503/f504 with various stability/ cost trade-offs. an external clock signal can be applied to oscin: in this case oscout must be grounded. to reduce costs, an rc circuit can be applied to the oscin pin to establish the internal clock frequency, instead of the quartz. without any connection, the device can work with its internal clock generator (10 mhz) reset . this signal is used to reset the ST52F500/ f503/f504 and re-initialize the registers and control signals. it is also used when switching from the programming mode to working mode and vice versa. pa0-pa7, pb0-pb7,pc0-pc5 . these lines are organized as i/o ports. each pin can be configured as an input, output (with pull-up, push-pull, weak- pull-up, open-drain, high-impedance), or as an interrupt source. t0out, t1out . these pins output the signals generated by the pwm/timer 0 and pwm/timer 1 peripheral. tres , tstrt, tclk . these pins are related to the pwm/timer 0 peripheral and are used for input capture and event counting. the tres pin is used to set/reset the timer; the tstrt pin is used to start/stop the counter. the timer can be driven by the internal clock or by an external signal connected to the tclk pin. int . this pin is used as input for the non-maskable (top level) interrupt. the interrupt signal is detected only if the pin is configured in alternate function. scl, sda . these pin are used respectively as serial clock and serial data i/o in i 2 c peripheral protocol. they are used also in programming mode to receive and transmit data. sck, miso, mosi, ss . these pins are used by the serial peripheral interface (spi) peripheral. sck is the serial clock line. miso (master in slave out) and mosi (master out slave in) are the serial data lines, which work in input or in output depending on if the device is working in slave or master mode. the ss pin allows the selection of the device master/slave mode.
ST52F500/f503/f504 15/94 2 internal architecture ST52F500/f503/f504's architecture is register file based and is composed of the following blocks and peripherals: n control unit (cu) n data processing unit (dpu) n decision processor (dp) n alu n memory interface n up to 256 bytes register file n program/data memory n data eeprom n interrupts controller n clock oscillator n plvd and por n digital i/o ports n timer/pwms n i 2 c n spi figure 2.1 cu block diagram 2.1 control unit and data processing unit the control unit (cu) decodes the instructions stored in the program memory and generates the appropriate control signals. the main parts of the cu are illustrated in figure 2.1. the five different parts of the cu manage loading, logic/arithmetic, jump, control and the fuzzy instruction set. the block called acollectoro manages the signals deriving from the different parts of the cu. the collector defines the signals for the data processing unit (dpu) and decision processor (dp), as well as for the different peripherals of the icu. the block called aarbitero manages the different parts of the cu, so that only one part of the system is activated during working mode. the cu structure is extremely flexible and was designed with the purpose of easily adapting the core of the microcontroller to market needs. new instruction sets or new peripherals can easily be included without changing the structure of the microcontroller, maintaining code compatibility. a set of 107 different instructions is available. each instruction requires a number of clock pulses to be performed that depends on the complexity of the instruction itself. the clock pulses to execute the instructions are driven directly by the masterclock, which has the same frequency of the oscillator signal supplied. loading instruction set logic arithmetic instruction set jump instruction set control instruction set decision processor instruction set c o l l e c t o r control signals a r b i t e r microcode clock master
ST52F500/f503/f504 16/94 figure 2.2 data processing unit (dpu) the dpu receives, stores and sends the instructions deriving from the program/data memory, register file or from the peripherals. it is controlled by the cu on the basis of the decoded instruction. the fuzzy registers store the partial results of the fuzzy computation. the accumulator register is used by the alu and is not accessible directly: the instructions used by the alu can address all the register file locations as operands, allowing a more compact code and a faster execution. the following addressing modes are available: inherent, immediate, direct, indirect, bit direct. 2.1.1 program counter. the program counter (pc) is a 16-bit register that contains the address of the next memory location to be processed by the core. this memory location may be both an instruction or data address. the program counter's 16-bit length allows the direct addressing of a maximum of 64 kbytes in the program/data memory space. the pc can be changed in the following ways: n jp (jump) pc = jump address n interrupt pc = interrupt vector n reti pc = pop (stack) n ret pc = pop (stack) n call pc = subroutines address n reset pc = reset vector n normal instruction pc = pc + 1 2.1.2 flags. the st five core includes different sets of flags that correspond to 2 different modes: normal mode and interrupt mode. each set of flags consist of a carry flag (c), zero flag (z) and sign flag (s). each set is stacked: one set of flags is used during normal operation and other sets are used during each level of interrupt. formally, the user has to manage only one set of flags: c, z and s since the flag stack operation is performed automatically. program counter register file 256 bytes register file address accumulator decision registers alu flags reg. memory address peripherals control unit program memory input registers peripherals interrupts unit processor
ST52F500/f503/f504 17/94 each interrupt level has its own set of flags, which is saved in the flag stack during interrupt servicing. these flags are restored from the flag stack automatically when a reti instruction is executed. if the icu was in normal mode before an interrupt, after the reti instruction is executed, the normal flags are restored. note: a subroutine call is a normal mode execution. for this reason a ret instruction, consequent to a call instruction, doesn't affect the normal mode set of flags. flags are not cleared during context switching and remain in the state they were in at the exit of the last interrupt routine switching. the carry flag is set when an overflow occurs during arithmetic operations, otherwise it is cleared.the sign flag is set when an underflow occurs during arithmetic operations, otherwise it is cleared. the flags, related to the current context, can be checked by reading the flags input register 38 (026h). figure 2.3 multiplication 2.2 arithmetic logic unit the 8-bit arithmetic logic unit (alu) performs arithmetic calculations and logic instructions such as: sum, subtraction, bitwise and, or, xor, bit set and reset, bit test and branch, right/left shift and rotate (see the chapter 9 instruction set for further details). in addition, the alu of ST52F500/f503/f504 can perform multiplication (mult) and division (div). multiplication is performed by using 8 bit operands storing the result in 2 registers (16 bit values); the division instruction addresses the msb of the dividend (the lsb is stored in the next address): the result and remainder are stored in these source addresses (see figure 2.3 and figure 2.4). in order to manage signed type values, the alu also performs addition and subtraction with offset (addo and subo). these instructions respectively subtract and add 128 to the overall result, in order to manage values logically in the range between -128,127. figure 2.4 division ram 000h 001h 002h i j+1 j-1 j 0ffh 0fdh 0feh reg. j reg. i lsb msb x 16 bit ram i j+1 j-1 j reg. j reg. j+1 remainder quotient reg. i : i-1 i+1 000h 001h 002h 0ffh 0fdh 0feh
ST52F500/f503/f504 18/94 2.3 register description flags register (flag) input register 38 (026h) read only reset value: 0000 0000 (00h) bit 7-3: not used bit 2: z zero flag bit 1: s sign flag bit 0: c carry flag 70 -----zsc
ST52F500/f503/f504 19/94 3 addressing spaces ST52F500/f503/f504 has six separate addressing spaces: n register file n program/data memory n stacks n input registers n output registers n configuration registers each space is addressed by a load type instruction that indicates the source and the destination space in the mnemonic code (see figure 3.1). 3.1 memory interface the read/write operation in the space addresses are managed by the memory interface, which can recognize the type of memory addressed and set the appropriate access time and mode. in addition, the memory interface manages the in application programming (iap) functions in flash devices like writing cycle and memory write protection. figure 3.1 addressing spaces 3.2 register file the register file consists of up to 256 general purpose 8-bit ram locations called aregisterso in order to recall the functionality. the register file exchanges data with all the other addressing spaces and is used by the alu to perform all the arithmetic and logic instructions. these instructions have any register file address as operands. data can be moved from one location to another by using the ldrr instruction; see further ahead for information on the instruction used to move data between the register file and the other addressing spaces. 3.3 program/data memory the program/data memory consists of both non- volatile memory (flash, eeprom) and ram memory benches. non-volatile memory (nvm) is mainly used to store the user program and can also be used to store permanent data (constant, look-up tables). each ram bench consists of 128/256 locations used to store run-time user data. at least one bench is present in the devices. ram benches are also used to implement both system and user stacks. cu dpu alu peripheral block register file input registers non volatile memory ram banks and stacks program/data memory stfive core on chip peripherals output registers configuration registers peripheral block peripheral block lder ldre ldri ldce ldcr decision processor registers ldfr ldpe ldpr ldcnf program counter pgsetr getpg
ST52F500/f503/f504 20/94 nvm is always located beginning after the first locations of the addressing space. ram banks are always located after nvm. nvm is organized in accordance to the following blocks (see figure 3.2): n reset vector block (from address 0 to 2) contains an absolute jump instruction to the first user program instruction. the assembler tool automatically fills these locations with correct data. n interrupt vectors block (from location 3 up to 32) contains the interrupt vectors. each address is composed of three bytes (the jump opcode and the 16 bit address). interrupt vectors are set by using irq pseudo-instruction (see the programming manual). figure 3.2 program/data memory organization n mbfs setting block (just after the interrupt vectors) contains the coordinates of the vertexes of every mbf defined in the program. the last address that can be assigned to this block is 1023. this area is dynamically assigned according to the size of the fuzzy routines. the memory area that remains unused, if any, is assigned to the program instructions block. n the program instructions block (just after the last mbf data through the last nvm address) contains the instruction of the user program and the permanent data. n option bytes block (from location 3000h to 307fh) is the addressing space reserved for the option bytes. in ST52F500/f503/f504, only the location from 3000h to 3007h are used. reset vector interrupt vectors membership functions parameters program instructions and permanent data program instructions and permanent data system stack data user stack ram benchs non volatile memory option bytes ~~ 0000h 0003h 0021h 0400h 3000h 307fh ff00h ffffh ~~
ST52F500/f503/f504 21/94 flash and eeprom are programmed electrically just applying the supply voltage (2.4 v to 5.5 v) and it is also erased electrically; this feature allows the user to easily reprogram the memory without taking the device off from the board (in situ programming isp). data and commands are transmitted through the i 2 c serial communication protocol. data can also be written run-time with the in application programming (iap) nvm can be locked by the user during the programming phase, in order to prevent external operation such as reading the program code and assuring protection of user intellectual property. flash and eeprom pages can be protected by unintentional writings. the operations that can be performed on the nvm during the programming phase, isp and iap are described in detail in the section 4. figure 3.3 system and user stack 3.4 system and user stacks the system and user stacks are located in the program/data memory in the ram benches. system stacks are used to push the program counter (pc) after an interrupt request or a subroutine call. after a ret (return from a subroutine) or a reti (return from an interrupt) the pc that is saved is popped from the stack and restored. after an interrupt request, the flags are also saved in a reserved stack inside the core, so each interrupt has its own flags. the system stack is located in the last ram bench starting from the last address (255) inside the bench page. the system stack pointer (ssp) can be read and modified by the user. for each level of stack 2 bytes of the ram are used. the ssp points to the first currently available stack position. when a subroutine call or interrupt request occurs, the content of the pc is stored in a couple of locations pointed to by the ssp that is decreased by 2. 20ffh 2000h 2001h 20feh register file configuration registers user stack top msb user stack top lsb program counter ram bench system stack pointer user stack pointer user data page number location adress irq reti pop x push x register x lsb msb system stack system stack system stack system stack level 1 level 2 level 3 level 4 user stack level 1 user stack level 2 user stack level 3 user stack level 4
ST52F500/f503/f504 22/94 when a return occurs (ret or reti instruction), the ssp is increased by 2 and the data stored in the pointed locations couple is restored back into the pc. the current ssp can be read and write in the couple of configuration registers 44 02ch (msb: page number, always 32 020h) and 45 02dh (lsb: location address) (see figure 3.3). in ST52F500/ f503/f504 the user can only consider the lsb because the msb is always the same. the user stack is used to store user data and is located beginning from a ram bench location set by the user (ustp) by writing the couple of configuration registers 5 005h (msb: page number) and 6 005h (lsb: location address) (see figure 3.3). register 5, which is the page number, must always be set to a value between 32 (020h) and 255 (0ffh): values higher than 32 always address ram on page 32. this feature allows a flexible use of the user stack in terms of dimension and to avoid overlaps. the user stack pointer (usp) points to the first currently available stack location. when the user stores a byte value contained in the register file by using the push instruction, the value is stored in the position pointed to by the usp that is increased (the user stack order is opposite to the system stack one). when the user takes a value from the user stack with the pop instruction, the usp is decreased and the value pointed to is copied in the specified register file location. by writing the ustp, the new address is automatically written in the usp. the current usp can be read from the input registers 75 04bh (msb: page number, always 32 020h) and 76 04ch (lsb: location address) (see figure 3.3). in ST52F500/f503/f504 the user can only consider the lsb because the msb is always the same. note: the user must pay close attention to avoid overlapping user and stacks data. the user stack top location and the system stack pointer should be configured with care in order to have enough space between the two stacks. 3.5 input registers the ST52F500/f503/f504 input registers bench consists of a file of 8-bit registers containing data or the status of the peripherals. for example, the input registers contain data converted by the adc, ports, serial communication peripherals, timers, etc. the input registers can be accessed by using the ldri instruction that loads the specified register file address with the contents of the specified input register. see the programming manual for further details on this instruction. the input registers are read-only registers. in order to simplify the concept, a mnemonic name is assigned to each register. the same name is used in visual five development tools. the list of the input registers is shown in table 3.1. 3.6 output registers the ST52F500/f503/f504 output registers bench consists of a file of 8-bit registers containing data sent to the peripherals and the i/o ports (for example: timer counters, data to be transmitted by the serial communication peripherals, data to be sent to the port pins in output, etc.). the registers are located inside the peripherals and ports, which allow flexibility and modularity in the design of new family devices. the output registers are write only. in order to access the configuration register the user can use the following instructions: n ldpi: loads the immediate value in the specified output register. n ldpr: loads the contents of the specified register file location into the output register specified. this instruction allows computed data to be sent to peripherals and ports. n ldpe direct: loads the contents of the specified program/data memory location into the output register specified. this instruction allows data to be sent to peripherals and ports from a table. n ldpe indirect: loads the contents of the program/data memory location whose address is contained in the specified register file location into the output register specified. this instruction allows data to be sent to peripherals and ports from a table pointed to by a register. see the programming manual for further details about these instructions. in order to simplify the concept, a mnemonic name is assigned to each register. the same name is used in visual five development tools. the list of the output registers is shown in table 3.2. 3.7 configuration registers & option bytes the ST52F500/f503/f504 configuration registers bench consists of a file of 8-bit registers that allows the configuration of all the icu blocks. the registers are located inside the block they configure in order to obtain greater flexibility and modularity in the design of new family devices. in the configuration registers, each bit has a
ST52F500/f503/f504 23/94 peculiar use, so the logic level of each of them must be considered. some special configuration data, that needs to be load at the start-up and not further changed, are stored in option bytes. these are loaded only during the device programming phase. see table 3.3 and section 4 for a detailed description of the option bytes. the configuration registers are readable and writable; the addresses refer to the same register both in read and in write. in order to access the configuration register the user can work in several modes by utilizing the following instructions: n ldci: loads the immediate value in the configuration register specified and is the most commonly used to write configuration data. n ldcr: loads the configuration register specified with the contents of the specified register file location, allowing a parametric configuration. n ldce: loads the configuration register specified with the contents of the specified program/data memory location, allowing the configuration data to be taken from a table. n ldcnf: loads the register file location specified with the contents of the configuration register indicated, allowing for the inspection of the configuration of the device (permitting safe run-time modifications). in order to simplify the concept, a mnemonic name is assigned to each register. the same name is used in visual five development tools. the list of the configuration registers is shown in table 3.4.
ST52F500/f503/f504 24/94 table 3.1 input registers mnemonic description address port_a_in port a data input register 0 00h port_b_in port b data input register 1 01h port_c_in port c data input register 2 02h - not used 3 03h - not used 4 04h spi_in serial peripheral interface data input register 5 05h i2c_in i 2 c interface data input register 6 06h i2c_sr1 i 2 c interface status register 1 7 07h i2c_sr2 i 2 c interface status register 2 8 08h - not used 9 09h - not used 10 0ah usp_h user stack pointer (msb) 11 0bh usp_l user stack pointer (lsb) 12 0ch - not used 13-20 0dh- 014h pwm0_count_in_h pwm/timer 0 counter input register (msb) 21 015h pwm0_count_in_l pwm/timer 0 counter input register (lsb) 22 016h pwm0_status pwm/timer 0 status register 23 017h pwm0_capture_h pwm/timer 0 capture register (msb) 24 018h pwm0_capture_l pwm/timer 0 capture register (lsb) 25 019h pwm1_count_in_h pwm/timer 1 counter input register (msb) 26 01ah pwm1_count_in_l pwm/timer 1 counter input register (lsb) 27 01bh pwm1_status pwm/timer 1 status register 28 01ch pwm1_capture_h pwm/timer 1 capture register (msb) 29 01dh pwm1_capture_l pwm/timer 1 capture register (lsb) 30 01eh - not used 31-37 01fh- 025h flags flag register 38 026h - not used 39 027h iap_sr in application programming status register 40 028h
ST52F500/f503/f504 25/94 table 3.2 output registers mnemonic description address port_a_out port a data output register 0 00h port_b_out port b data output register 1 01h port_c_out port c data output register 2 02h - not used 3 03h - not used 4 04h spi_out serial peripheral interface data output register 5 05h i2c_out i 2 c interface data output register 6 06h pwm0_count_out_h pwm/timer 0 counter output register (msb) 7 07h pwm0_count_out_l pwm/timer 0 counter output register (lsb) 8 08h pwm0_reload_h pwm/timer 0 reload register (msb) 9 09h pwm0_reload_l pwm/timer 0 reload register (lsb) 10 0ah pwm1_count_out_h pwm/timer 1 counter output register (msb) 11 0bh pwm1_count_out_l pwm/timer 1 counter output register (lsb) 12 0ch pwm1_reload_h pwm/timer 1 reload register (msb) 13 0dh pwm1_reload_l pwm/timer 1 reload register (lsb) 14 0eh table 3.3 option bytes mnemonic description address osc_cr oscillator control register 0 00h clk_set clock parameters 1 01h osc_set oscillator set-up 2 02h pldv_cr programmable low voltage detector control register 3 03h wdt_en hw/sw watchdog selector 4 04h pg_lock first page write protected 5 05h pg_unlock first page not write protected 6 06h wakeup wake up from halt time 7 07h
ST52F500/f503/f504 26/94 table 3.4 configuration registers mnemonic description address int_mask interrupt mask register 0 00h int_pol interrupts polarity and lvd enable register 1 01h int_prl_h interrupt priority register (higher priority) 2 02h int_prl_m interrupt priority register (medium priority) 3 03h int_prl_l interrupt priority register (lower priority) 4 04h ustp_h user stack top pointer (msb) 5 05h ustp_l user stack top pointer (lsb) 6 06h wdt_cr watchdog configuration register 7 07h - not used 8 08h pwm0_cr1 pwm/timer 0 configuration register 1 9 09h pwm0_cr2 pwm/timer 0 configuration register 2 10 0ah pwm0_cr3 pwm/timer 0 configuration register 3 11 0bh pwm1_cr1 pwm/timer 1 configuration register 1 12 0ch pwm1_cr2 pwm/timer 1 configuration register 2 13 0dh - not used 14 0eh - not used 15 0fh i2c_cr i 2 c interface control register 16 010h i2c_ccr i 2 c interface clock control register 17 011h i2c_oar1 i 2 c interface own address register 1 18 012h i2c_oar2 i 2 c interface own address register 2 19 013h spi_cr serial peripheral interface control register 20 014h spi_status_cr serial peripheral interface control-status register 21 015h - not used 22 016h - not used 23 017h port_a_pullup port a pull up enable/disable register 24 018h port_a_or port a option register 25 019h
ST52F500/f503/f504 27/94 port_a_ddr port a data direction register 26 01ah port_a_af port a alternate function selection register 27 01bh port_b_pullup port b pull up enable/disable register 28 01ch port_b_or port b option register 29 01dh port_b_ddr port b data direction register 30 01eh port_b_af port b alternate function selection register 31 01fh port_c_pullup port c pull up enable/disable register 32 020h port_c_or port c option register 33 021h port_c_ddr port c data direction register 34 022h - not used 35-43 023h- 02bh ssp_h system stack pointer (msb) 44 02ch ssp_l system stack pointer (lsb) 45 02dh cpu_clk cpu clock prescaler 46 02eh table 3.4 configuration registers mnemonic description address
ST52F500/f503/f504 28/94 4 memory programming ST52F500/f503/f504 provides an on-chip user programmable non-volatile memory, which allows fast and reliable storage of user data. program/data memory addressing space is composed by a single voltage flash memory and a ram memory bench. the st52f503/504 devices also have a data eeprom bench to store permanent data with long term retention and a high number of write/erase cycles. all the program data memory addresses can execute code, including ram and eeprom benches. the memory is programmed by setting the v pp pin equal to v dd . data and commands are transmitted through the i 2 c serial communication protocol. the same procedure is used to perform ain-situo the programming of the device after it is mounted in the user system. data can also be written in run- time with the in-application programming (iap). the memory can be locked by the user during the programming phase, in order to prevent external operation such as reading the program code and assuring protection of user intellectual property. flash and eeprom pages can be protected by unintentional writings. 4.1 program/data memory organization the program/data memory is organized as described in section 3.3. the various sales types have different amounts of each type of memory. table 4.1 describes the memory benches amount and page allocation for each sales type. remark: some devices have ram or eeprom memory benches of 128 bytes. the address range inside the page of these benches is between 128 to 255. the addressing spaces are organized in pages of 256 bytes. each page is composed by blocks of 32 bytes. memory programming is performed one block at a time in order to speed-up the programming time (about 2.5 ms per block). the whole location address is composed as follows: 15 87 54 0 page add ress block address address insi de the block table 4.1 sales type memory organization device flash memory ram memory eeprom memory amount pages amount page amount page(s) ST52F500x0xx 1024 bytes 0 to 3 128 bytes 32* - - ST52F500x1xx 2048 bytes 0 to 7 128 bytes 32* - - ST52F500x2xx 4096 bytes 0 to 15 256 bytes 32 - - ST52F500x3xx 8192 bytes 0 to 31 256 bytes 32 - - st52f503x0xx 896 bytes 0 to 3 128 bytes 32* 128 bytes 3* st52f503x1xx 1920 bytes 0 to 7 128 bytes 32* 128 bytes 7* st52f503x2xx 3840 bytes 0 to 14 256 bytes 32 256 bytes 15 st52f503x3xx 7936 bytes 0 to 30 256 bytes 32 256 bytes 31 st52f504x0xx 4096 bytes 0 to 15 256 bytes 32 512 bytes 16-17 st52f504x1xx 4096 bytes 0 to 15 256 bytes 32 1024 bytes 16-19 st52f504x2xx 4096 bytes 0 to 15 256 bytes 32 2048 bytes 16-23 st52f504x3xx 4096 bytes 0 to 15 256 bytes 32 4096 bytes 16-31 (*) addresses range from 128 to 255 inside the page
ST52F500/f503/f504 29/94 4.2 memory programming the programming procedure writes the user program and data into the flash memory, eeprom and option bytes. the programming procedures are entered by setting the v pp pin equal to v dd and releasing the reset signal. the following pins are used in programming mode: n v pp used to switch to programming mode n v dd device supply n v ss device ground n reset device reset n scl i 2 c serial clock n sda i 2 c serial data during the device programming, the internal clock is used, so the oscin and oscout pins don't have to be considered. 4.2.1 programming mode start. the following sequence starts the programming mode: 1. v pp is set to v dd 2. the device is reset (reset=v ss ) 3. the reset is released (reset=v dd ) 4. the internal oscillator starts at 10 mhz 5. the memory is turned on 6. the i 2 c interface and ports are initialized 7. the i 2 c interface is configured to work as slave, receiver, 7-bit address and waits for data 8. the start signal is sent to the chip followed by the slave address 1010000 and the direction bit set to 0 (the addressed slave waits for da- ta). the device sends the acknowledge 9. the programming mode code 00000000 is sent and acknowledged 10. a command code is sent to the device 11. the procedure related to the command is ex- ecuted table 4.2 programming mode commands command code data in data out erase description blockwrite 00000001 32 - yes write the currently addressed block with the 32 bytes following the command. the block locations are erased before being written. bytewrite 00000010 2 - yes write the byte addressed by the next data sent in the currently addressed page. blockerase 00000011 1 yes erase the block addressed by the next data sent and inside the currently addressed page. byteerase 00000100 1 yes erase the byte addressed by the next data sent and inside the currently addressed page. byteread 00000101 1 1 - read the byte addressed by the next data sent and inside the current page. the read data is sent by the device after the re-send of the slave address with the r/w bit changed. globalerase 00001001 - - yes all the memory is erased. fastblockwrite 00001011 32 - no write the currently addressed block with the 32 bytes following the command. the block locations aren't erased. setpage 00001100 1 - - the currently addressed page is set with the next data sent. readdata 00001101 - 1 - read the memory location currently addressed. the read data is sent by the device after the command is acknowledged. the current memory absolute address is post-incremented. incblock 00001111 - - - the current block address is incremented modulo 8 (address 0 follows after address 7 and the page is post- incremented) readstatus 00010011 - 1 - this command is followed by a status data byte. mostly used in error condition and to check if the device is locked
ST52F500/f503/f504 30/94 figure 4.1 commands and data communication sequences the generic procedure of commands execution, with the data communication in both directions is displayed in figure 4.1. remark: the slave address 1010000 must be sent after a stop (i.e. each time the data direction changes, to specify the r/w bit). for example: if a command to send data to the device has been executed, a command for receiving data must be followed by the slave address and the r/w bit must be set to 1. the programming mode code doesn't need to be specified again . warning: after entering the programming mode, the currently pointed address is the page 48, block 3, byte 0 (lock byte). the list of the available commands in programming mode is showed in table 4.2 4.2.2 fast programming procedure. the fastest way to program the device memory is the use of the fastblockwrite command. the following procedure can be used to write the memory with a new program and new data, starting from the first memory location: 1. the programming mode is entered with the sequence described above 2. the memory is erased (all bits are put to 0) with the globalerase command. the device holds the scl line low, releasing it after the command is completed (about 2 ms). this command also unlocks the device if locked. 3. the fastblockwrite command is sent and the device acknowledges it 4. the 32 bytes of data to be written in the first memory block are sent in a sequence. the device acknowledges each of them 5. after the device acknowledges the 32nd byte, it holds the scl line until the parallel writing of the 32 byte is completed (about 2.5 ms) 6. the block pointer is incremented by sending the incblock command 7. the procedure is repeated from point 3 until there is data to be sent to the memory note: the block pointer assumes values between 0 to 7 (there are 8 blocks in a page). when the block pointer is equal to 7, the incblock command puts this pointer to 0 and increments the page pointer. the page pointer, after page writing is completed, does't have to be incremented in the procedure above described. 4.2.3 random data writing. a single byte can be written in a specified memory location by using the following procedure: 1. the programming mode is entered with the sequence described in section 4.2.1 2. the setpage command is sent, followed by the page number where the data should be written 3. the bytewrite command is sent followed by two bytes 4. the first bytes that follows the bytewrite com- mand is the address inside the pointed page where the data must be written. 5. the second byte is the data to be written 6. the device held the scl line low until the data is not stored in the memory (about 4.5 ms: 2 ms for erasing and 2.5 for writing) programming mode start sequence execution of commands for writing data: execution of commands for reading data: s=start, p=stop, a=acknowledge, na=non-acknowledge from slave to master from master to slave s 1010000 0 a 00000000 a command a data1 a ..... datan a p command a data1 a ..... datan a command a data1 a ..... datan a p command a address a p s 1010000 1 a data read na p
ST52F500/f503/f504 31/94 a similar procedure can be used to write a single block: 1. the setpage command is sent, followed by the page number where the data should be written 2. the incblock command is sent as many times as the block number inside the page (for ex- ample: to address the block 3 the incblock must be sent 3 times) 3. the writeblock command is sent followed by the 32 data bytes to be written. 4. after the 32th byte is sent, the device holds the scl line low until all the data are not stored in the memory (about 4.5 ms: 2 ms for erasing and 2.5 for writing: the same time for a single byte) the procedures described previously can be repeated as many time as needed, without exiting from programming mode or re-sending the slave address again. the commands byteerase and blockerase, used instead of bytewrite and blockwrite, erase (put all bit to 0) the specified memory location or block. 4.2.4 option bytes programming. the option byte addresses cannot be accessed with a sequential procedure like the one described in section 4.2.2. actually, the pointers are automatically incremented up to the last block or address in page 31. a further increment sets all the pointers to 0. the option byte addresses (located at page 48, block 0, addresses 0-7) must be accessed with a direct addressing procedure as the one described in section 4.2.3. if the fast programming procedure is used, it must be followed by a random block writing procedure to program the option bytes. the other 24 bytes of the block can be written with dummy values. figure 4.2 programming procedures fast programming procedure random byte writing procedure random block writing procedure option byte writing procedure s=start, p=stop, a=acknowledge, na=non-acknowledge from slave to master from master to slave s 10100000 a 00000000 a globalerase a fastblockwrite a data0 a .... . ..... data31 a fastblockwrite a data0 a ..... data31 a ..... ..... data31 a p ..... setpage a page address a bytewrite a byte address a data a command ..... ..... setpage a page address a incblock a ..... incblock a blockwrite a data0 a ..... ..... data31 a command ..... ..... setpage a 00110000 a writeblock a option byte 0 a ..... option byte 7 a ..... ..... dummy 0 a ..... dummy 23 a p
ST52F500/f503/f504 32/94 figure 4.3 reading and erasing procedures 4.3 memory verify to verify the memory contents or just to read part of data stored in memory, the byteread and the readdata command can be used. the first instruction needs the specification of the address; the second one allows the sequential reading of consecutive memory locations. since the device is aslaveo for the i 2 c protocol, after receiving a command for reading, it must be configured as slave transmitter to send the data. in order to do so, the slave address (1010000) must be sent again with the r/w byte set to 1, as stated by the communication protocol. 4.3.1 fast read procedure. the memory can be read sequentially by using the following procedure: 1. the programming mode is entered with the sequence described in section 4.2.1 2. the pointers address the memory location 0 3. the readdata command is sent and the de- vice acknowledges it. 4. the master generates a stop condition fol- lowed by a start condition 5. the slave address with the r/w byte set to 1 (10100001) is sent. the device receives the slave address and acknowledges it. 6. the device sends the data to be read in the serial data line sda. the current absolute ad- dress is post-incremented. 7. the master device doesn't send the acknowl- edge and generates a stop condition. 8. to read the next data, the master generates a start condition followed by the slave address with the r/w byte set to 0 (10100000). the device receives the slave address and ac- knowledges it. 9. the sequence restarts from point 3 until there is data to be read. remark: for the same reasons explained in section 4.2.4 the option bytes cannot be read with this procedure: they can be read with a direct addressing procedure as the one explained in the next section. fast reading procedure random byte reading procedure byte erasing procedure block erasing procedure s=start, p=stop, a=acknowledge, na=non-acknowledge from slave to master from master to slave s 10100000 a 00000000 a readdata a p s 1010000 1 a data read na p ..... ..... s 10100000 a readdata a p s 1010000 1 a data read na p ..... data read na p ..... setpage a page address a byteread a byte address a p s 1010000 1 a ..... ..... data read na p s 1010000 0 a command ..... ..... setpage a page address a byteerase a byte address a command ..... ..... setpage a page address a incblock a ..... incblock a blockerase a command .....
ST52F500/f503/f504 33/94 4.3.2 random data reading. to read a specified memory location, the following procedure should be used: 1. the programming mode is entered with the sequence described in section 4.2.1 2. the setpage command is sent, followed to the page number where the data to be read is located 3. the byteread command is sent, followed by an address inside the page 4. the master generates a stop condition fol- lowed by a start condition 5. the slave address with the r/w byte set to 1 (10100001) is sent. the device receives the slave address and acknowledges it. 6. the device sends the data to be read in the serial data line sda. 7. the master device doesn't send the acknowl- edge and generates a stop condition. 8. to send the next command, the master should generate a start condition followed by the slave address with the r/w byte set to 0 (10100000). figure 4.4 device lock procedure 4.4 memory lock the program/data memory space can be locked to inhibit the reading of contents and protect the intellectual property. to lock the device, the user must set all the bit of the lock byte to `1'. the lock byte is located on page 48 (030h), block 3, byte 0 inside the block i.e. byte 96 (060h) inside the page. after writing 255 (0ffh) into the lock byte, with the procedure described in the section 4.2.3, the memory is locked and the only command allowed are the following: globalerase : this command, writing `0' in all the memory, also unlock the device. readdata : the only block that can be read is the block 3 in page 48 (030h); this allows the read- ing of the lock byte and the id code locations (see section 4.5). readstatus : this command allows the detection of an error condition in programming mode op- eration (see section 4.6). it can also be used to check if the device is locked. remark: the lock byte is checked when entering the programming mode. for this reason after writing the lock byte, all the commands can be carried out until the programming mode is exited. device lock procedure device lock and id code writing procedure device lock reading procedure s=start, p=stop, a=acknowledge, na=non-acknowledge from slave to master from master to slave ..... setpage a 00110000 a bytewrite a 01100000 a 11111111 a command ..... ..... setpage a 00110000 a incblock a incblock a incblock a blockwrite a ..... ..... 11111111 a id code 1 a id code 2 a ..... id code 31 a command ..... ..... setpage a 00110000 a byteread a 01100000 a p s 1010000 1 a ..... ..... lock byte na p s 1010000 0 a command .....
ST52F500/f503/f504 34/94 figure 4.5 error handling procedure when the device is locked, if memory reading is attempted, with the exception of the lock byte and id code block, the device returns no data and an error sequence. if memory writing is attempted in any memory location, the device doesn't carry out the command and returns an error sequence. to unlock the device the globalerase command must be executed before any writing or reading command. 4.5 id code block 3 in page 48 (030h) can also be read if the device is locked. the first byte of the block is the lock byte, the other 31 locations are available to the user for writing data, as for example identification codes to distinguish the firmware version loaded in the device. the id code must be written before locking the device: after the device is locked it can only be read. the use of the block writing procedure is the fastest way: the id code is written together the lock byte, which is sent first, then the 31 bytes of id code follow. note: the id code cannot be modified if the device is locked: it can only be read. 4.6 error cases if a wrong command or data is sent to the device, it generates an error condition by not sending the acknowledge after the first successive data or command. figure 4.5 shows the error sequence. the error case can be handled by using the readstatus command. this command can be sent after the error condition is detected; the device returns a status byte containing the error code. the readstatus command sequence is showed in figure 4.5. the list of the error codes is illustrated in table 4.3. remark: after the readstatus command execution or after any error, the start sequence must be carried out before sending a new command. the most significative bit of the error codes indicates (when set to `1') that the memory is locked. when a command, that is not allowed when the memory is locked, is sent, the a not allowedo code is sent. if another code is sent with the msb to `1' it indicates that the error condition is not caused by the memory lock, but by the event related with the code sent. warning: when the data writing into a non existing location is attempted, no error condition is generated. the user must take care in specifying the correct page address. wrong command/data case handling: s=start, p=stop, a=acknowledge, na=non-acknowledge from slave to master from master to slave wrong command/data a command/data na readstatus a p s 1010000 1 a status byte na p table 4.3 error codes name code description wrong direction x0000001 a transmit direction, not correct in the running sequence, has been set stop missed x0000010 the master missed generating a necessary stop condition data missing x0000011 the master missed to send necessary data to the device receive error x0000100 the data sent by the master hasn't been received correctly by the device wrong command x0000101 the master sent a wrong command code not allowed x0000110 a command not allowed when the device is locked has been sent wrong mode x0010000 a code different form the programming mode code (00000000) has been sent
ST52F500/f503/f504 35/94 4.7 in-situ programming (isp) the program/data memory can be programmed using the isp mode. this mode allows the device to be programmed when it is mounted in the user application board. this feature can be implemented by adding a minimum number of components and board impact. the programming procedures and pins used are identical to the ones described before for the standard programming mode. all the features previously described in this chapter are applicable in isp mode. if reset, scl and sda pins are used in the user application board for other purposes, it is recommended to use a serial resistor to avoid a conflict when the other devices force the signal level. the isp can be applied by using the standard tools for the device programming. the ST52F500 starter kit supplies a cable to perform the isp. the user application board should supply a suited connector type for the cable (see starter kit user manual). 4.8 in-application programming (iap) the in application programming mode (iap) allows the writing of user data in the flash and eeprom memories when the user program is running. there are two ways to write data in iap mode: single byte write and block write. both procedures take about 4.5 ms to complete the writing: the block write allows the writing of 32 byte in parallel. remark: during data writing, the execution of the user program is stopped until the procedure is completed. interrupt requests stop the writing operation and the data may be not stored. the bit abrt in the iap_sr input register signals that the data writing hasn't been completed. to assure writing completion, the user should globally disable the interrupts (udgi instruction) before starting iap data writing. 4.8.1 single byte write. writing of a single byte in the non-volatile program/data memory is performed by using the lder instruction (both direct and indirect addressing). the memory page should be indicated before the lder instruction with the pgset or pgsetr instruction. the byte address inside the page is specified by the lder instruction itself. as soon as the instruction is executed, the data writing starts and is performed in about 4.5 ms. 4.8.2 block write. this procedure allows the writing of 32 bytes in parallel. these bytes should belong to the same block. before the writing in the program/data memory, data must be buffered in the register file in the first 32 locations (0-31, 00h-020h) by using the normal instructions to load the register file locations. then the data writing starts by using the blkset instruction. the destination block is addressed by specifying the memory page with the pgset or pgsetr instruction before to start the writing; the block inside the page is addressed with the argument of the blkset instruction. example: pgset 5 blkset 4 this instruction sequence writes the contents of the first 32 bytes of the register file in the locations 1152-1183 (0480h-049fh). warning: the user should be careful in specifying the correct page and block: the addressing of an not existing block can cause the unwanted writing of a different block. as soon as the blkset instruction is executed, the data writing starts and is performed in about 4.5 ms. this procedure may also be used to write few data, taking in account that all the 32 byte are written in the block anyway. 4.8.3 memory corruption prevention. the user can protect some pages (or all the memory) from unintentional writings. the only constraint is that the protected pages must be consecutive. two option bytes allow the specification of the page to be protected: pg_lock (option byte 5) and pg_unlock (option byte 6). pg_lock is used to specify the first protected page; pg_unlock is used to specify the first page not protected after the protected ones. the pages between the two addresses are protected. when writing in a protected page is attempted, the procedure is aborted and the bit prtcd of iap_sr input register is set. if the pg_lock and pg_unlock have the same value, no page is protected. by default, the two option bytes are programmed with the value 0, so the memory is not write protected by default. in programming mode the protection is not considered and the pages can be written unless the device is locked.
ST52F500/f503/f504 36/94 4.8.4 option bytes. first protected page (pg_lock) option byte 5 (05h) reset value: 0000 0000 (00h) bit 7-0: lck7-0 first page write protected in this register the address of first page to be protected in writing is specified. the pages following this one are protected up to the page specified by the pg_unlock option byte (not included among the protected ones). first page not protected (pg_unlock) option byte 6 (06h) reset value: 0000 0000 (00h) bit 7-0: unlck7-0 first page not write protected in this register the address of first page not write protected after the protected ones is specified. the pages following this one aren't protected. 4.8.5 input register. iap status register (iap_sr) input register 40 (028h) read only reset value: 0000 0000 (00h) bit 7-2: not used bit 1: prtcd page protected 0: the writing has been completed 1: the writing has been aborted because the page is protected. bit 0: abrt writing operation aborted 0: the writing has been completed 1: the writing has been aborted because an interrupt or another unspecified cause occurred. the abrt and prtcd bits are reset after the next successful data writing in the flash of eeprom memory. 70 lck7 lck6 lck5 lck4 lck3 lck2 lck1 lck0 70 unlck7 unlck6 unlck5 unlck4 unlck3 unlck2 unlck1 unlck0 70 - - - - - - prtcd abrt
ST52F500/f503/f504 37/94 5 interrupts the control unit (cu) responds to peripheral events and external events through its interrupt channels. when such events occur, if the related interrupt is not masked and doesn't have a priority order, the current program execution can be suspended to allow the cu to execute a specific response routine. each interrupt is associated with an interrupt vector that contains the memory address of the related interrupt service routine. each vector is located in the program/data memory space at a fixed address (see figure 3.2 program/data memory organization). 5.1 interrupt processing if interrupts are pending at the end of an arithmetic or logic instruction, the interrupt with the highest priority is acknowledged. when the interrupt is acknowledged the flags and the current pc are saved in the stacks and the associated interrupt routine is executed. the start address of this routine (interrupt vector) is located in three bytes of the program/data memory between address 3 and 32 (03h-020h). see table 5.1 for the list of the interrupt vector addresses. the interrupt routine is performed as a normal code. at the end of each instruction, the cu checks if a higher priority interrupt has sent an interrupt request. an interrupt request with a higher priority stops lower priority interrupts. the program counter and the flags are stored in their own stacks. with the instruction reti (return from interrupt) the flags and the program counter (pc) are restored from the top of the stacks. these stacks have already been described in paragraph 3.4. an interrupt request cannot stop fuzzy rule processing, but only after the end of a fuzzy rule or at the end of a logic or arithmetic instruction, unless a global interrupt disable instruction has been executed before (see below). remark: a fuzzy routine can be interrupted only in the main program. when a fuzzy function is running inside another interrupt routine an interrupt request can cause side effects in the control unit. for this reason, in order to use a fuzzy function inside an interrupt routine, the user must include the fuzzy function between an udgi (mdgi) instruction and an uegi (megi) instruction (see the following paragraphs), in order to disable the interrupt request during the execution of the fuzzy function. figure 5.1 interrupt flow 5.2 global interrupt request enabling when an interrupt occurs, it generates a global interrupt pending (gip). after a gip a global interrupt request (gir) will be generated and interrupt service routine associated with the interrupt with higher priority will start. in order to avoid possible conflicts between the interrupt masking set in the main program, or inside high level language compiler macros, the gip is put in and through the user global interrupt mask or the macro global interrupt mask (see figure 5.2). the uegi/udgi instruction switches the user global interrupt mask enabling/disabling the gir for the main program. megi/mdgi instructions switch the macro global interrupt mask on/off in order to ensure that the macro will not be interrupted. figure 5.2 global interrupt request normal program flow interrupt service routine reti instruction interrupt global interrupt pending user global interrupt mask macro global global interrupt request
ST52F500/f503/f504 38/94 5.3 interrupt sources st five manages interrupt signals generated by the internal peripherals or generated by software by the trap instruction or coming from the port pins. there are two kinds of interrupts coming from the port pins: the nmi and the ports interrupts. nmi (not maskable interrupt) is associated with pin pa7 when it is configured as alternate function. this interrupt source doesn't have a configurable level priority and cannot be masked. the fixed priority level is lower than the software trap and higher than all the other interrupts. the nmi can be configured to be active on the rising or the falling edge. the port interrupts sources are connected with port a and port b pins. the pins belonging to the same port are associated with the same interrupt vector: there is one vector for port a and one for port b. in order to use one port pin as interrupt, it must be configured as an interrupt source (see i/o ports chapter). in this manner, up to 16 port interrupt sources are available. by reading the port the sources that belong to the same port can be discriminated. the port interrupts can be configured to be active on the rising or the falling edge. all the interrupt sources are filtered, in order to avoid false interrupt requests caused by glitches. the trap instruction is something between a interrupt and a call: it generated an interrupt request at top priority level and the control is passed to the associated interrupt routine which vector is located in the fixed addresses 30-32. this routine cannot be interrupted and it is serviced even if the interrupts are globally disabled. note: similarly to the call instruction, after a trap the flags are not stacked. figure 5.3 example of interrupt requests 5.4 interrupt maskability and priority levels interrupts can be masked by the corresponding int_mask configuration register 0 (00h). an interrupt is enabled when the mask bit is a1o. vice versa, when the bit is a0o, the interrupt is masked and the eventual requests are kept pending. all the interrupts, with the exception of the nmi and trap that have fixed level priority, have a config- urable priority level. the configuration of the prior- ity levels is completed by writing three consecutive configuration registers: int_priority_h, int_priority_m, int_priority_l, addresses from 2 to 4 (02h-04h). the 24 bits of these registers are divided into 8 groups of three bits: each group is associated with a priority level. the three bits of each group are written with the code number asso- ciated with the interrupt source. see table 5.1 to know the codes. remark: the priority levels configuration registers must be programmed with different values for each 3-bit groups to avoid erroneous operation. for this reason the interrupt priority must be fixed at the beginning of the main program, because the reset values of the configuration registers correspond to an undefined configuration (all zeros). during program execution the interrupt priority can only be modified within the main program: it cannot be changed within an interrupt service routine. 5.5 interrupt reset when an interrupt is masked, all requests are not acknowledged and remain pending. when the pending interrupt is enabled it is immediately serviced. this event may be undesired; in order to avoid this a rint instruction may be inserted followed by the code number that identifies the interrupt to reset the pending request. see table 5.1 to know the codes. main program 5 4 3 2 1 0 int2 int0 int2 int1 int2 int3 int4 main program priority level int2 int0 int4 int1 int3 6
ST52F500/f503/f504 39/94 5.6 register description interrupt mask register (int_mask) configuration register 0 (00h) read/write reset value: 0000 0000 (00h) bit 7: mskpb interrupt mask port b 0: port b interrupt masked 1: port b interrupt enabled bit 6: mskpa interrupt mask port a 0: port a interrupt masked 1: port a interrupt enabled bit 5: mski2c interrupt mask i 2 c interface 0: i 2 c interface interrupt masked 1: i 2 c interface interrupt enabled bit 4: mskspi interrupt mask spi 0: spi interrupt masked 1: spi interrupt enabled bit 3: not used bit 2: mskt1 interrupt mask pwm/timer 1 0: pwm/timer 1 interrupt masked 1: pwm/timer 1 interrupt enabled bit 1: mskt0 interrupt mask pwm/timer 0 0: pwm/timer 0 interrupt masked 1: pwm/timer 0 interrupt enabled bit 0: not used interrupt polarity register (int_pol) configuration register 1 (01h) read/write reset value: 0000 0000 (00h) bit 7-5: not used bit 4-3: see timer 0 registers description bit 2: polpb port b interrupt polarity 0: the port b interrupt is triggered on the rising edge of the applied external signal. 1: the port b interrupt is triggered on the falling edge of the applied external signal. bit 1: polpa port a interrupt polarity 0: the port a interrupt is triggered on the rising edge of the applied external signal. 1: the port a interrupt is triggered on the falling edge of the applied external signal. bit 0: polnmi non maskable interrupt polarity 0: the nmi is triggered on the rising edge of the applied external signal. 1: the nmi is triggered on the falling edge of the applied external signal. high priority register (int_prl_h) configuration register 2 (02h) read/write reset value: 0000 0000 (00h) medium priority register (int_prl_m) configuration register 3 (03h) read/write reset value: 0000 0000 (00h) low priority register (int_prl_l) configuration register 4 (04h) read/write reset value: 0000 0000 (00h) 70 mskpb mskpa mski2c mskspi - mskt1 mskt0 - 70 - - - t0rpol respol strpol polpa polnmi 70 prl23 prl22 prl21 prl20 prl19 prl18 prl17 prl16 70 prl15 prl14 prl13 prl12 prl11 prl10 prl9 prl8 70 prl7 prl6 prl5 prl4 prl3 prl2 prl1 prl0
ST52F500/f503/f504 40/94 these three register are used to configure the priority level of each interrupt source. the 24 bits of these registers (prl24-prl0) are divided into 8 groups of three bits: each group is associated with a priority level (from level 1, the highest, to level 8, the lowest: level 0 is fixed for the nmi that can be interrupted only by the trap) . the three bits of each group are written with the code number associated with the interrupt source (see table 5.1). prl2-prl1 : interrupt priority level 1 (highest) prl5-prl3 : interrupt priority level 2 prl8-prl6 : interrupt priority level 3 prl11-prl9 :interrupt priority level 4 prl14-prl12 : interrupt priority level 5 prl17-prl15 : interrupt priority level 6 prl20-prl18 : interrupt prioritylevel 7 prl23-prl21 : interrupt priority level 8 (lowest) example: writing the code 110 into prl8-prl6 bits the priority level 3 is assigned to the port a interrupt. warning: the priority level configuration registers must be always configured. table 5.1 interrupt sources paramethers interrupt source priority type prl code rint code maskable vector addresses pwm/timer 0 programmable 001 1 yes 6-8 (06h-08h) pwm/timer 1 programmable 010 2 yes 9-11 (09h-0bh) spi programmable 100 4 yes 15-17 (0fh-011h) i 2 c interface programmable 101 5 yes 18-20 (012h-014h) port a programmable 110 6 yes 21-23 (015h-017h) port b programmable 111 7 yes 24-26 (018h-01ah) nmi fixed - 8 no 27-29 (01bh-01dh) trap fixed to highest - - no 30-32 (01eh-020h)
ST52F500/f503/f504 41/94 6 clock, reset & power saving modes 6.1 clock the ST52F500/f503/f504 clock generator module generates the internal clock for the internal control unit, alu and on-chip peripherals. the clock is designed to require a minimum of external components. ST52F500/f503/f504 devices supply the internal oscillator in four clock modes: n external oscillator n external clock n external rc oscillator n internal clock the device always starts in internal clock mode, excluding any external clock source. after the start-up phase the clock is configured according to the user definition programmed in the option bytes 0 (osc_cr). the internal clock generator can supply an internal clock signal with a fixed frequency of 10 mhz 1%, without the need for external components. in order to obtain the maximum accuracy, the frequency can be calibrated by configuring the related option byte 2 (osc_set). the external oscillator mode uses a quartz crystal or a ceramic resonator connected to oscin and oscout as illustrated in figure 6.1. this figure also illustrates the connection of an external clock. the ST52F500/f503/f504 oscillator circuit generates an internal clock signal with the same period and phase as the oscin input pin. the maximum frequency allowed is 24 mhz. when the external oscillator is used, the loop gain can be adapted to the various frequencies values by configuring the three bits of the option byte 1 clk_set (see register decription, table 6.2). when an external clock is used, it must be connected to the pin oscin while oscout can be floating. in this case, option byte 1 bits must be written with 0 (000). the crystal oscillator start-up time is a function of many variables: crystal parameters (especially r s ), oscillator load capacitance (cl), ic parameters, environment temperature and supply voltage. the crystal or ceramic leads and circuit connections must be as short as possible. typical values for cl1, cl2 are 10pf for a 20 mhz crystal. the clock signal can also be generated by an external rc circuit offering additional cost savings. figure 6.1 illustrates the possible connections. frequency is a function of resistor, capacitance, supply voltage and operating temperature; some indicative values when vdd=5v and t=25 , are shown in table 6.1. the clock signal generates two internal clock signals: one for the cpu and one for the peripherals. the cpu clock frequency can be reduced, in order to decrease current consuption, by setting the cpu_clk configuration register 46 (02eh). the cpu clock can be reduced up to 64 times (see register description). figure 6.1 oscillator connections oscin oscout st five oscin st five oscout crystal clock external clock cl1 10pf cl2 10pf clock input oscin st five oscout rc circuit clock vdd vss rc table 6.1 rc oscillator indicative frequencies c (pf) r( w ) f osc (khz) variation 20 pf 9.5k 5000 6.6% 10k 4870 7.1% 20k 3000 5.3% 50k 1360 3.3% 100k 724 2.8% 100 pf 10k 1720 7.5% 20k 926 8% 50k 424 11.2% 100k 248 15%
ST52F500/f503/f504 42/94 6.2 reset four reset sources are available: n reset pin (external source) n watchdog (internal source) n power on reset (internal source) n plvd reset (internal source) when a reset event occurs, the user program restarts from the beginning. 6.2.1 external reset. reset is an input pin. an internal reset does not affect this pin. a reset signal originated by external sources is recognized immediately. the reset pin may be used to ensure vdd has risen to a point where the icu can operate correctly before the user program is run. reset must be set to vdd in working mode. a pull up resistor of 100 k w guarantees that the reset pin is at level a1o when no halt or power- on events occur. if an external resistor is connected to the reset pin a minimum value of 10k w must be used. 6.2.2 reset procedures. after the reset pin is set to vdd or following a power-on reset event, the device is not started until the internal supply voltage has reached the nominal level of 2.5 v (corresponding roughly to vdd=2.8 v). figure 6.2 reset block diagram after this level has been reached, the internal oscillator (10 mhz) is started and a delay period of 4.096 clock cycles is initiated, in order to allow the oscillator to stabilize and to ensure that recovery has taken place from the reset state. if the device has been configured to work with the internal clock, the user program is started, otherwise the option byte 7 (wakeup) is read and another count is started before running the user program. the count duration depends on the contents of the option byte 7 (wakeup), that works as a prescaler, according to the follwing formula: this delay has been introduced in order to ensure that the oscillator has become stable after its restart. if the reset is generated by the plvd or the watchdog, the oscillator is not turned off; for this reason the cpu is then restarted immediately, without the delay. after a reset procedure is completed, the core reads the instruction stored in the first 3 bytes of the program/data memory, which contains a jump instruction to the first instruction of the user program. the assembler tool automatically generates this jump instruction with the first instruction address. po wer-on reset vdd vdd reset counter x 4096 plvd vdd in tern a l re set w atc hd og res et plvd r eset rst_d elay watchdog clk_mode delay 4096 wakeup 1 + () tclk =
ST52F500/f503/f504 43/94 6.3 programmable low voltage detector the on-chip programmable low voltage detector (plvd) circuit prevents the processor from falling into an unpredictable status if the power supply drops below a certain level. when vdd drops below the detection level, the plvd causes an internal processor reset that remains active as long as vdd remains below the trigger level. the plvd resets the entire device except the power-on detector and the plvd itself. the plvd can be enabled/disabled at reset by setting the option byte 2 (plvd_cr) bits. when vdd increases above the trigger level, the plvd reset is deactivated and the user program is started from the beginning. the detection levels are programmable by means of the option byte 2 (plvd_cr). there are three levels for the plvd falling voltages (2.9v, 3.4v, 3.9v) and for rising voltages (3.1v, 3.65v, 4.2v). the hysteresis for each level are respectively 200 mv, 250 mv and 300 mv. the plvd circuit will only detect a drop if vdd voltage stays below the safe threshold for at least 5 m s before activation/deactivation of the lvd in order to filter voltage spikes. the plvd function isn't active when it is in halt mode. 6.4 power saving modes there are two types of power saving modes: wait and halt mode. these conditions may be entered by using the wait or halt instructions. 6.4.1 wait mode. wait mode places the icu in a low power consumption status by stopping the cpu. all peripherals and the watchdog remain active. during wait mode the interrupts are enabled. the icu remains in wait mode until an interrupt or a reset occurs, whereupon the program counter jumps to the interrupt service routine or, if a reset occurs, to the beginning of the user program. 6.4.2 halt mode. halt mode is the lowest icu power consumption mode, which is entered by executing the halt instruction. the internal oscillator is turned off, causing all internal processing to be terminated, including the operations of the on-chip peripherals. halt mode cannot be used when the watchdog is enabled. if the halt instruction is executed while the watchdog system is enabled, it will be skipped without modifying the normal cpu operations. the icu can exit halt mode upon reception of an nmi, a port interrupt or a reset. the internal oscillator (10 mhz) is started and a delay period of 4.096 clock cycles is initiated, in order to allow the oscillator to stabilize and to ensure that recovery has taken place from the reset state. if the device has been configured to work with the internal clock, the user program is started, otherwise the option byte 7 (wakeup) is read and another count is started before running the user program. the count duration depends on the contents of the option byte 7 (wakeup), that works as prescaler, according to the follwing formula: this delay has been introduced in ordet to ensure that the oscillator has become stable after it is restarted. after the start up delay, by exiting with the nmi or a port interrupt, the cpu restarts operations by serving the associated interrupt routine. warning: if the port interrupt is masked, the icu exits from the halt mode and jumps to the lower priority interrupt routine. figure 6.3 wait flow chart delay 4096 wakeup 1 + () tclk = oscillator peripherals clock cpu clock interrupts on on off enab. wait istruction reset interrupt yes no cpu clock on program counter reset no jump to int. routine cpu clock on normal program flow
ST52F500/f503/f504 44/94 figure 6.4 halt flow chart halt instruction watchdog enabled halt instruction skipped yes no oscillator off peripherals clock off cpu clock off restart program servicing the interrupt routine (*) nmi or port interrupt no yes no yes reset reset cpu and restart user program oscillator on peripherals clock on cpu clock on 4096 internal clock cycles delay oscillator on peripherals clock on cpu clock on 4096 internal clock cycles delay yes no internal clock ? internal clock ? 4096 x (wakeup+1) clock cycles delay 4096 x (wakeup+1) clock cycles delay no yes (*) warning: if the port interrupt is masked, the icu exits from the halt mode and jumps to the lower priority interrupt routine.
ST52F500/f503/f504 45/94 6.5 register description the following section describes the register which are used to configure the clock, reset and plvd. 6.5.1 configuration register. cpu clock prescaler (cpu_clk) configuration register 46 (02eh) read/write reset value: 0000 0000 (00h) bit 7-6: not used bit 5-0: cpuck5-0 cpu clock prescaler bits the cpu clock frequency is divided by a factor described in the following table 6.5.2 option bytes. clock mode (osc_cr) option byte 0 (00h) reset value: 0000 0000 (00h) bit 7-2: not used bit 1-0: ckmod1-0 clock mode 00: internal oscillator 01: external clock or quartz 1x: external rc oscillator external clock parameters (clk_set) option byte 1 (01h) reset value: 0000 0000 (00h) bit 7-3: not used bit 2-0: ckpar2-0 oscillator gains these three bits enable/disable the loop gains when a external clock or quartz are used for generating the clock. the following table decribes the possible configuration options. table 6.2 illustrates the reccomended values for the most common frequencies used, time to start the oscillations and the settling time to have a duty cycle of 40%-60% (at steady state it is 50%). warning: if an external clock is used instead of a quartz or ceramic resonator, it is reccomended that no gain be enabled (ckpar2-0=000) in order lo lower the current consuption. 70 - - cpuck5 cpuck4 cpuck3 cpuck2 cpuck1 cpuck0 cpuck5-0 cpu clock 000000 f cpu =f osc 000001 f cpu =f osc /2 000010 f cpu =f osc /4 000100 f cpu =f osc /8 001000 f cpu =f osc /16 010000 f cpu =f osc /32 100000 f cpu =f osc /64 others f cpu =f osc /64 70 ------ ckmod1 ckmod0 70 - - - - - ckpar2 ckpar1 ckpar0 ckpar2-0 enabled gain stages 000 no gains (external clock mode) 001 1 gain stage enabled 010 not allowed 011 3 gain stage enabled 100 not allowed 101 4 gain stage enabled 110 not allowed 111 6 gain stage enabled
ST52F500/f503/f504 46/94 (*) values by design (not characterized) internal oscillator calibration (osc_set) option byte 2 (02h) reset value: 0000 0000 (00h) bit 7-6: not used bit 5-0: ospar5-0 internal oscillator parameters these bits are used in order to calibrate the precision of the internal oscillator working at 10 mhz. the six bits enable some current generators with steps of 5 m a corresponding to interval of frequency of 100khz . warning: the maximum configuration value allowed is 101000 (40). the value coresponding to the 10 mhz by design is 010100 (20). plvd control register (plvd_cr) option byte 3 (03h) reset value: 0000 0000 (00h) bit 7-2: not used bit 1-0: plvd1-0 plvd detection levels 00: plvd disabled 01: lowest detection level 10: medium detection level 11: highest detection level wake-up time prescaler (wakeup) option byte 7 (07h) reset value: 0000 0000 (00h) bit 7-0: wk7-0 wake-up prescaler this byte determinates the time delay for the stabilization of the oscillator after an external reset or a por and after the wake-up from halt. the time delay is computed according to the following formula: warning: the value 255 for wakeup is not allowed. if the internal clock is used as clock source the prescaler is not used. table 6.2 recomended gains for the most common frequencies frequency recommend gain stages ckpar2-0 oscillatio n start times* settling times for 40%-60% duty-cycle* external clock 0 000 - - 5 mhz 1 001 100 m s110 m s 10 mhz 3 011 80 m s85 m s 20 mhz 6 111 133 m s 143 m s 70 - - ospar5 ospar4 ospar3 ospar2 ospar1 ospar0 70 ------ plvd1 plvd0 70 wk7 wk6 wk5 wk4 wk3 wk2 wk1 wk0 delay 4096 wakeup 1 + () tclk =
ST52F500/f503/f504 47/94 7 i/o ports 7.1 introduction ST52F500/f503/f504 are characterized by flexible individually programmable multi-functional i/o lines. the ST52F500/f503/f504 supplies devices with up to 3 ports (named from a to c) with up to 22 i/o lines. each pin can be used as a digital i/o or can be connected with a peripheral (alternate function). the i/o lines belonging to port a and port b can also be used to generate port interrupts. the i/o port pins can be configured in the following modes: n input high impedance (reset state) n input with pull-up n output with pull-up n output push-pull n output with weak pull-up n output open drain n interrupt with pull-up n interrupt without pull-up these eight modes can be selected by programming three configuration registers for each port. all the pins that belong to the same port can be configured separately by setting the corresponding bits in the three registers (see register description). to avoid side effects, the configuration registers register are latched only when the direction register (port_x_ddr) is written. for this reason this register must be always written when modifying the pin configuration. the i/o digital pins (port a, c) are ttl compatible and have a schmitt trigger. the output buffer can supply high current sink (up to 8ma). figure 7.1 digital pin 7.2 input mode the pins configured as input can be read by accessing the corresponding port input register by means of the ldri instruction. the addresses for port a , b and c are respectively 0 (00h), 1 (01h), and 2 (02h). when executing the ldri instruction all the signals connected to the input pins of the port are read and the logical value is copied in the specified register file location. if some pins are configured in output, the port buffer contents, which are the last written logical values in the output pins, are read. 7.3 output mode the pins configured as output can be written by accessing the corresponding port output register by means of the ldpr, ldpi and ldpe instructions. the addresses for port a , b and c are respectively, 0 (00h), 1 (01h), and 2 (02h). when executing the above mentioned instructions, the port buffer is written and the port pin signals are modified. if some pins are configured as input or as interrupt, the values are ignored. 7.4 interrupt mode the pins configured as interrupt mode can generate a port interrupt request. only port a and port b pins can be configured in this mode. an interrupt vector is associated to each port: there are two port interrupts available but more pins of the ports can act as source at the same time. the configuration registers switch the signals deriving from interrupt pins to an or gate that generates the interrupt request signal. the signal deriving from the pins can be read, allowing the discrimination of the interrupt sources when more than one pin can generate the interrupt signal. the interrupt trigger can be configured either in the rising or falling edge of the external signal. figure 7.2 analog pin pad pull up enable digital out enable da t a out por t a,c, d,e pi n da t a in pad analog switc h pu l l up e nab le dig it al out en ab le data ou t data in an al og data in an alo g switch en abl e p o rt b pin
ST52F500/f503/f504 48/94 7.5 alternate functions the alternate function allows the pins to be connected with the peripheral signals or nmi. not all port pins have an alternate function associated. a configuration register (port_x_af) for each port is used to switch from the digital i/o function or the alternate function. some pins can have two alternate functions: one input function and one output function. to switch between the two functions, the port_x_af must be configured in alternate function mode and the port_x_ddr configuration register must be switched in input mode or in output mode. nmi is considered an alternate function. for this reason an nmi interrupt request can't be generated unless the pa7 pin is configured in alternate function and in one of the input modes. figure 7.3 port pin architecture when an on-chip peripheral is configured to use a pin, the correct i/o mode of the related pin should be selected by selecting one of the appropriate modes. see the registers description in order to obtain the right configurations.some peripherals, as for example the i 2 c peripheral, directly drive the pin configuration according to the current function, overriding the user configuration. 7.6 register description in order to configure the port's pins, the three configuration registers port_x_pullup, port_x_or and port_x_ddr must be configured. the combination of these three registers determine the pin's configuration, according to the scheme shown in table 7.1. in order to select between the digital functions or alternate functions port_x_af register must be configured. each bit of the configuration registers configures the pin of the corresponding position (example: port_a_ddr bit 5 configures the pin pa5). conf. reg. d e c o d e r ff register file alte rnate function inte rrupt polarity irq t o inpu t register vdd digital port pin int pu sel en enable data conf. reg. conf. reg. conf. reg.
ST52F500/f503/f504 49/94 7.6.1 configuration registers. port a pull-up register (port_a_pullup) configuration register 24 (018h) read/write reset value: 0000 0000 (00h) bit 7-0: pua7-6 port a pull-up (see table 7.1) 0: port a pin without pull-up 1: port a pin with pull-up port a option register (port_a_or) configuration register 25 (019h) read/write reset value: 0000 0000 (00h) bit 7-0: ora7-6 port a option (see table 7.1) port a data direction register (port_a_ddr) configuration register 26 (01ah) read/write reset value: 0000 0000 (00h) bit 7-0: ddra7-6 port a direction (see table 7.1) 0: port a pin configured as input 1: port a pin configured as output port a alternate fuction (port_a_af) configuration register 27 (01bh) read/write reset value: 0000 0000 (00h) bit 7: afa7 alternate function pa7 0: digital i/o 1: int bit 6: afa6 alternate function pa6 0: digital i/o 1: t0out bit 5: afa5 alternate function pa5 0: digital i/o 1: tclk bit 4: afa4 alternate function pa4 0: digital i/o 1: tstrt bit 3: afa3 alternate function pa3 0: digital i/o 1: tres bit 2: afa2 alternate function pa2 0: digital i/o 1: t1out bit 1: afa1 alternate function pa1 0: digital i/o 1: sda bit 0: afa0 alternate function pa0 0: digital i/o 1: scl 70 pua7 pua6 pua5 pua4 pua3 pua2 pua1 pua0 70 ora7 ora6 ora5 ora4 ora3 ora2 ora1 ora0 70 ddra7 ddra6 ddra5 ddra4 ddra3 ddra2 ddra1 ddra0 70 afa7 afa6 afa5 afa4 afa3 afa2 afa1 afa0 table 7.1 pin mode configuration mode pu or ddr input high impedance 0 0 0 input with pull-up 1 0 0 interrupt without pull-up 0 1 0 interrupt with pull-up 1 1 0 output push-pull 0 0 1 output with pull-up 1 0 1 output open drain 0 1 1 output weak pull-up 1 1 1
ST52F500/f503/f504 50/94 port b pull-up register (port_b_pullup) configuration register 28 (01ch) read/write reset value: 0000 0000 (00h) (*) not used in 20 pin pa ckage devices (** ) not used in 16 pin package devices bit 7-0: pub7-6 port b pull-up (see table 7.1) 0: port b pin without pull-up 1: port b pin with pull-up port b option register (port_b_or) configuration register 29 (01dh) read/write reset value: 0000 0000 (00h) (*) not used in 20 pin pa ckage devices (** ) not used in 16 pin package devices bit 7-0: orb7-6 port b option (see table 7.1) port b data direction register (port_b_ddr) configuration register 30 (01eh) read/write reset value: 0000 0000 (00h) (*) not used in 20 pin pa ckage devices (** ) not used in 16 pin package devices bit 7-0: ddrb7-6 port b direction (see table 7.1) 0: port b pin configured as input 1: port b pin configured as output port b alternate fuction (port_b_af) configuration register 31 (01fh) read/write reset value: 0000 0000 (00h) note: this register is not used in 16 pin devices bit 7-4: not used bit 3: afb3 alternate function pb3 0: digital i/o 1: ss bit 2: afb2 alternate function pb2 0: digital i/o 1: sdi bit 1: afb1 alternate function pb1 0: digital i/o 1: sdo bit 0: afb0 alternate function pb0 0: digital i/o 1: sck port c pull-up register (port_c_pullup) configuration register 32 (020h) read/write reset value: 0000 0000 (00h) note: this register is not used in 16/20 pin devices bit 7-6: not used bit 5-0: puc7-6 port c pull-up (see table 7.1) 0: port c pin without pull-up 1: port c pin with pull-up port c option register (port_c_or) configuration register 33 (021h) read/write reset value: 0000 0000 (00h) note: this register is not used in 16/20 pin devices bit 7-6: not used bit 5-0: orc7-6 port c option (see table 7.1) 70 pub7* pub6* pub5** pub4** pub3** pub2** pub1 pub0 70 orb7* orb6* orb5** orb4** orb3** orb2** orb1 orb0 70 ddrb7* ddrb6* ddrb5** ddrb4** ddrb3** ddrb2** ddrb1 ddrb0 70 - - - - afb3 afb2 afb1 afb0 70 - - puc5 puc4 puc3 puc2 puc1 puc0 70 - - orc5 orc4 orc3 orc2 orc1 orc0
ST52F500/f503/f504 51/94 port c data direction register (port_c_ddr) configuration register 34 (022h) read/write reset value: 0000 0000 (00h) note: this register is not used in 16/20 pin devices bit 7-6: not used bit 5-0: ddrc7-6 port c direction (see table 7.1) 0: port c pin configured as input 1: port c pin configured as output note: in order to achieve low current consuption, the port pins must be configured as input pull-up, even though they are not existing in the package. for example in 20 pin devices, the pins pb6-7 and pc0-7 must be configured in input pull-up. 7.6.2 input registers. port a data input register (port_a_in) input register 0 (00h) read only reset value: xxxx xxxx bit 7-0: pai7-0 port a input data the logical level applied in the port a pins, configured as digital input, can be achieved by reading this register. port b data input register (port_b_in) input register 1 (01h) read only reset value: xxxx xxxx (*) not used in 20 pin pa ckage devices (** ) not used in 16 pin package devices bit 7-0: pbi7-0 port b input data the logical level applied in the port b pins, configured as digital input, can be achieved by reading this register. port c data input register (port_c_in) input register 2 (02h) read only reset value: xxxx xxxx note: this register is not used in 16/20 pin devices bit 7-6: not used bit 5-0: pci5-0 port c input data the logical level applied in the port c pins, configured as digital input, can be achieved by reading this register. 7.6.3 output registers. port a data output register (port_a_out) output register 0 (00h) write only reset value: 0000 0000 (00h) bit 7-0: pao7-0 port a output data the logical values written in these register bits are put in the port a pins configured as digital output. port b data output register (port_b_out) output register 1 (01h) write only reset value: 0000 0000 (00h) (*) not used in 20 pin package devices (**) not use d in 16 pin package devices bit 7-0: pbo7-0 port b input data 70 - - ddrc5 ddrc4 ddrc3 ddrc2 ddrc1 ddrc0 70 pai7 pai6 pai5 pai4 pai3 pai2 pai1 pai0 70 p bi 7* pbi6* pbi5** pbi4** pbi3** pbi2** pbi1 pbi0 70 - - pci5 pci4 pci3 pci2 pci1 pci0 70 pao7 pao6 pao5 pao4 pao3 pao2 pao1 pao0 70 p bo 7* pbo6* pbo5** pbo4** pbo3** pbo2** pbo1 pbo0
ST52F500/f503/f504 52/94 the logical values written in these register bits are put in the port b pins configured as digital output. port c data output register (port_c_out) output register 2 (02h) write only reset value: 0000 0000 (00h) note: this register is not used in 16/20 pin devices bit 7-6: not used bit 5-0: pco7-0 port c input data the logical values written in these register bits are put in the port c pins configured as digital output. 70 - - pco5 pco4 pco3 pco2 pco1 pco0
ST52F500/f503/f504 53/94 8 fuzzy computation (dp) the ST52F500/f503/f504 decision processor (dp) main features are: n up to 8 inputs with 8-bit resolution; n 1 kbyte of program/data memory available to store more than 300 to membership functions (mbfs) for each input; n up to 128 outputs with 8-bit resolution; n possibility of processing fuzzy rules with an unlimited number of antecedents; n unlimited number of rules and fuzzy blocks. the limits on the number of fuzzy rules and fuzzy program blocks are only related to the program/data memory size. 8.1 fuzzy inference the block diagram shown in figure 8.1 describes the different steps performed during a fuzzy algorithm. the ST52F500/f503/f504 core allows for the implementation of a mamdami type fuzzy inference with crisp consequents. inputs for fuzzy inference are stored in 8 dedicated fuzzy input registers. the ldfr instruction is used to set the input fuzzy registers with values stored in the register file. the result of a fuzzy inference is stored directly in a location of the register file. 8.2 fuzzyfication phase in this phase the intersection (alpha weight) between the input values and the related mbfs (figure 8.2) is performed. eight fuzzy input registers are available for fuzzy inferences. figure 8.1 fuzzy inference figure 8.2 alpha weight calculation after loading the input values by using the ldfr assembler instruction, the user can start the fuzzy inference by using the fuzzy assembler instruction. during fuzzyfication: input data is transformed in the activation level (alpha weight) of the mbf's. 8.3 inference phase the inference phase manages the alpha weights obtained during the fuzzyfication phase to compute the truth value ( w ) for each rule. this is a calculation of the maximum (for the or operator) and/or minimum (for the and operator) performed on alpha values according to the logical connectives of fuzzy rules. several conditions may be linked together by linguistic connectives and/or, not operators and brackets. the truth value w and the related output singleton are used by the defuzzyfication phase, in order to complete the inference calculation. 11 1m n1 nm fuzzyfication inference phase defuzzyfication n rules n rules -1 2 1 input values output values 1 a ij j-th mbf i-th input variable
ST52F500/f503/f504 54/94 figure 8.3 fuzzyfication 8.4 defuzzyfication in this phase the output crisp values are determined by implementing the consequent part of the rules. each consequent singleton x i is multiplied by its weight values w i , calculated by the decision processor, in order to compute the upper part of the defuzzyfication formula. each output value is obtained from the consequent crisp values (x i ) by carrying out the following defuzzyfication formula: where: i = identifies the current output variable n = number of the active rules on the current output w ij = weight of the j-th singleton x ij = abscissa of the j-th singleton the decision processor outputs are stored in the ram location i-th specified in the assembler instruction out i. 8.5 input membership function the decision processor allows the management of triangular mbfs. in order to define an mbf, three different parameters must be stored on the program/data memory (see figure 8.4): n the vertex of the mbf: v ; n the length of the left semi-base: lvd ; n the length of the right semi-base: rvd ; in order to reduce the size of the memory area and the computational effort the vertical range of the vertex is fixed between 0 and 15 (4 bits) by using the previous memorization method different kinds of triangular membership functions may be stored. figure 8.5 shows some examples of valid mbfs that can be defined in ST52F500/ f503/f504. each mbf is then defined storing 3 bytes in the first kbyte of the program/data memory. the mbf is stored by using the following instruction: mbf n_mbf lvd v rvd where: n_mbf is a tag number that identifies the mbf lvd , v , and rvd are the parameters that describe the mbf's shape as described above. figure 8.4 mbfs parameters input 1 x1 a 1 input 2 x2 a2 or = max if input 1 is x1 or input 2 is x2 then ....... input 1 x1 a 1 input 2 x2 a2 if input 1 is x1 and input 2 is x2 then ....... y i x ij w ij j n w ij j n --------------------- = x 15 lvd rvd v 15 0 0 input mbf output singleton output variable input variable w
ST52F500/f503/f504 55/94 figure 8.5 example of valid mbfs 8.6 output singleton the decision processor uses a particular kind of membership function called singleton for its output variables. a singleton doesn't have a shape, like a traditional mbf, and is characterized by a single point identified by the couple (x, w), where w is calculated by the inference unit as described earlier. often, a singleton is simply identified with its crisp value x. figure 8.6 output membership functions 8.7 fuzzy rules rules can have the following structures: if a op b op c...........then z if (a op b) op (c op d op e...) ...........then z where op is one of the possible linguistic operators (and/or) in the first case the rule operators are managed sequentially; in the second one, the priority of the operator is fixed by the brackets. each rule is codified by using an instruction set, the inference time for a rule with 4 antecedents and 1 consequent is about 3 microseconds at 20 mhz. the assembler instruction set used to manage the fuzzy operations is reported in the table below. 1 i-th output 0 x ij x i0 x in w i0 w ij w in j-th singleton table 8.1 fuzzy instructions set instruction description mbf n_mbf ivd v rvd stores the mbf n_mbf with the shape identified by the parameters ivd , v and rvd is nm fixes the alpha value of the input n with the mbf m isnot nm calculates the complementary alpha value of the input n with the mbf m. fzand implements the fuzzy operation and fzor implements the fuzzy operation or con crisp multiplies the crisp value with the last w weight out n_out performs defuzzyfication and stores the currently fuzzy output in the register n_out fuzzy starts the computation of a sigle fuzzy variable () modify the priority in the rule evaluation
ST52F500/f503/f504 56/94 example 1 : if input 1 is not mbf 1 and input 4 is mbf 12 or input 3 is mbf 8 then crisp 1 is codified by the following instructions: example 2 , the priority of the operator is fixed by the brackets: if (input 3 is mbf 1 and input 4 is not mbf 15 ) or (input 1 is mbf 6 or input 6 is not mbf 14 ) then crisp 2 at the end of the fuzzy rules related to the current fuzzy variable, by using the instruction out reg , the specified register is written with the computed value. afterwards, the control of the algorithm returns to the cu. the next fuzzy variable evaluation must start again with a fuzzy instruction. isnot 1 1 calculates the not a value of input 1 with mbf 1 and stores the result in internal registers fzand implements the operation and between the previous and the next alpha value evaluated is 4 12 fixes the a value of input 4 with mbf 12 and stores the result in internal registers fzor implements the operation or between the previous and the next alpha value evaluated is 3 8 fixes the a value of input 3 with mbf 8 and stores the result in internal registers con crisp 1 multiplies the result of the last w operation with the crisp value crisp 1 ( parenthesis open to change the priority is 3 1 fixes the a value of input 3 with mbf 1 and stores the result in internal registers fzand implements the operation and between the previous and the next alpha value evaluated isnot 4 15 calculates the not a value of input 4 with mbf 15 and stores the result in internal registers ) parenthesis closed fzor implements the operation or between the previous and the next alpha value evaluated ( parenthesis open to change the priority is 1 6 fixes the a value of input 1 with mbf 6 and stores the result in internal registers fzor implements the operation or between the previous and the next alpha value evaluated isnot 2 14 calculates the not a value of input 6 with mbf 14 and stores the result in internal registers ) parenthesis closed con crisp 2 multiplies the result of the last w operation with the crisp value crisp 2
ST52F500/f503/f504 57/94 9 instruction set ST52F500/f503/f504 supplies 107 (98 + 9 fuzzy) instructions that perform computations and control the device. computational time required for each instruction consists of one clock pulse for each cycle plus 2 clock pulses for the decoding phase. total computation time for each instruction is reported in table 9.1 the alu of ST52F500/f503/f504 can perform multiplication (mult) and division (div). multiplication is performed by using 8 bit operands storing the result in 2 registers (16 bit values), see figure 2.3. division is performed between a 16 bit dividend and an 8 bit divider, the result and the remainder are stored in two 8-bit registers (see figure 2.4). 9.1 addressing modes ST52F500/f503/f504 instructions allow the following addressing modes: n inherent: this instruction type does not require an operand because the opcode specifies all the information necessary to carry out the instruction. examples: nop, scf. n immediate: these instructions have an operand as a source immediate value. examples: ldrc, addi. n direct: the operands of these instructions are specified with the direct addresses. the operands can refer (according to the opcode) to addresses belonging to the different addressing spaces. example: sub, ldre. n indirect: data addresses that are required are found in the locations specified as operands. both source and/or destination operands can be addressed indirectly. the operands can refer, (according to the opcode) to addresses belonging to different addressing spaces. examples: ldrr(reg1),(reg2); lder mem_addr,(reg1). n bit direct: operands of these instructions directly address the bits of the specified register file locations. examples: bset, btest. 9.2 instruction types ST52F500/f503/f504 supplies the following instruction types: n load instructions n arithmetic and logic instructions n bitwise instructions n jump instructions n interrupt management instructions n control instructions the instructions are listed in table 9.1 table 9.1 instruction set load instructions mnemonic instruction bytes cycles z s c blkset blkset const 2 (*) - - - getpg getpg regx 2 7 - - - ldce ldce confx,memy 3 8/9 - - - ldci ldci confx, const 3 7 - - - ldcnf ldcnf regx, conf 3 7 - - - ldcr ldcr confx, regy 3 8 - - - lder lder memx, regy 3 10 - - - lder lder (regx),(regy) 3 11 - - - lder lder (regx), regy 3 10 - - - lder lder memx,(regy) 3 11 - - - ldfr ldfr fuzzyx, regy 3 8 - - -
ST52F500/f503/f504 58/94 ldpe ldpe outx, memy 3 8/9 - - - ldpe ldpe outx, (regy) 3 9/10 - - - ldpi ldpi outx, const 3 7 - - - ldpr ldpr outx, regy 3 8 - - - ldrc ldrc regx, const 3 7 - - - ldre ldre regx, memy 3 8/9 - - - ldre ldre (regx), (regy) 3 10/11 - - - ldre ldre (regx), memy 3 9/10 - - - ldre ldre regx, (regy) 3 9/10 - - - ldri ldri regx, inpx 3 7 - - - ldrr ldrr regx, regy 3 9 - - - ldrr ldrr (regx), (regy) 3 10 - - - ldrr ldrr (regx), regy 3 9 - - - ldrr ldrr regx, (regy) 3 10 - - - pgset pgset const 2 4 - - - pgsetr pgsetr regx 2 5 - - - pop pop regx 2 7 - - - push push regx 2 8 - - - arithmetic instructions mnemonic instruction bytes cycles z s c add add regx, regy 3 9 i - i addc addc regx, regy 3 9 i - i addi addi regx, const 3 8 i - i addic addic regx, const 3 8 i - i addo addo regx, regy 3 11 i i i addoc addoc regx, regy 3 11 i i i addoi addoi regx, const 3 10 i i i addoic addoicregx,cons 3 10 i i i and and regx, regy 3 9 i - - andi andi regx,const 3 8 i - - cp cp regx, regy 3 8 i i - cpi cpi regx,const 3 7 i i - dec dec regx 2 7 i i - load instructions (continued)
ST52F500/f503/f504 59/94 div div regx, regy 3 16 i i i inc inc regx 2 7 i - i mirror mirror regx 2 7 i - - mult mult regx, regy 3 11 i - - not not regx 2 7 i - - or or regx, regy 3 9 i - - ori ori regx, const 3 8 i - - sub sub regx, regy 3 9 i i - subi subi regx, const 3 8 i i - subis subis regx, const 3 8 i i - subo subo regx, regy 3 11 i i i suboi suboi regx, 3 10 i i i subois suboisregx,const 3 10 i i i subos subos regx, regy 3 11 i i i subs subs regx, regy 3 9 i i - rcf rcf 1 4 - - i rsf rsf 1 4 - i - rzf rzf 1 4 i - - scf scf 1 4 - - i ssf ssf 1 4 - i - szf szf 1 4 i - - xor xor regx, regy 3 9 i - - xori xori regx, cons 3 8 i - - bitwise instructions mnemonic instruction bytes cycles z s c asl asl regx 2 7 i - i asr asr regx 2 7 i i - bnot bnot regx, bit 3 8 i - - bres bres regx, bit 3 8 i - - bset bset regx, bit 3 8 i - - btest btest regx, bit 3 7 i - - mtest mtest regx,const 3 7 i - - rlc rlc regx 2 7 i - i arithmetic instructions (continued)
ST52F500/f503/f504 60/94 rol rol regx 2 7 i - i ror ror regx 2 7 i i - rrs rrs regx 2 7 i i - jump instructions mnemonic instruction bytes cycles z s c call call addr 3 11 - - - jp jp addr 3 6 - - - jpc jpc addr 3 5/6 - - - jpnc jpnc addr 3 5/6 - - - jpns jpns addr 3 5/6 - - - jpnz jpnz addr 3 5/6 - - - jps jps addr 3 5/6 - - - jpz jpz addr 3 5/6 - - - ret ret 1 8 - - - interrupt management instructions mnemonic instruction bytes cycles z s c halt halt 1 4/13 - - - megi megi 1 6/11 - - - mdgi mdgi 1 5 - - - reti reti 1 9 - - - rint rint int 2 6 - - - udgi udgi 1 5 - - - uegi uegi 1 6/11 - - - trap trap 1 9 - - - waiti waiti 1 7/10 - - - control instructions mnemonic instruction bytes cycles z s c fuzzy fuzzy 1 4 - - - nop nop 1 5 - - - wdtrfr wdtrfr 1 6 - - - wdtslp wdtslp 1 5 - - - bitwise instructions (continued )
ST52F500/f503/f504 61/94 notes: regx, regy: register file address memx, memy: program/data memory addresses confx, confy: configuration registers addresses outx: output registers addresses inpx: input registers addresses const: constant value fuzzyx: fuzzy input registers i flag affected - flag not affected (*) the instruction blkset determines the start of a 32 byte block writing in flash or eeprom program/ data memory. during this phase (about 4 ms), the cpu is stopped to executing program instructions. the duration of the blkset instruction can be identified with this time.
ST52F500/f503/f504 62/94 10 watchdog timer 10.1 functional description the watchdog timer (wdt) is used to detect the occurrence of a software fault, usually generated by external interference or by unforeseen logical conditions, which causes the application program to abandon its normal sequence. the wdt circuit generates an icu reset on expiry of a programmed time period, unless the program refreshes the wdt before the end of the programmed time delay. sixteen different delays can be selected by using the wdt configuration register. after the end of the delay programmed by the configuration register, if the wdt is active, it starts a reset cycle pulling the reset signal low. once the wdt is activated, the application program has to refresh the counter (by the wdtsfr instruction) during normal operation in order to prevent an icu reset. in ST52F500/f503/f504 devices it is possible to choose between ahardwareo or asoftwareo watchdog. the hardware wdt allows the counting to avoid unwanted stops for external interferences. the first mode is always enabled unless the option byte 4 (wdt_en) is written with a special code (10101010b): only this code can switch the wdt in asoftwareo mode, the other 255 possibilities keep the ahardwareo mode enabled. when the software mode is enabled, it is possible to stop the wdt during the user program executions by using the wdtslp instruction. when the wdt is in hardware mode, neither the wdtslp instruction nor external interference can stop the counting. the ahardwareo wdt is always enabled after a reset. figure 10.1 watchdog block diagram the working frequency of wdt (pres clk in the figure 10.1) is equal to the clock master. the clock master is divided by 500, obtaining the wdt clk signal that is used to fix the timeout of the wdt. according to the wdt_cr configuration register values, a wdt delay between 0.1ms and 937.5ms can be defined when the clock master is 5 mhz. by changing the clock master frequency the timeout delay can be calculated according to the configuration register values. the first 4 bits of the wdt_cr register are used, obtaining 16 different delays. 10.2 register description sw watchdog enable (wdt_en) option byte 4 (04h) reset value: 0000 0000 (00h) bit 7-0: wdten7-0 sw watchdog enable byte writing the code 10101010 in this byte the software watchdog mode is enabled. d0 d1 d2 d3 configuration register reset wdtrfr pres clk = clk master wdtslp prescaler wdt reset generator reset wtd clk table 10.1 watchdog timing range (5 mhz) wdt timeout period (ms) min 0.1 max 937.5 70 wdten7 wdten6 wdten5 wdten4 wdten3 wdten2 wdten1 wdten0
ST52F500/f503/f504 63/94 watchdog control register (wdt_cr) configuration register 7 (07h) read/write reset value: 0000 0000 (00h) bit 7-4: not used bit 3-0: d3-0 watchdog clock divisor factor bits the watchdog clock (wdt clk) is divided by the numeric factor determined by these bits, according with table 10.2 and the following formula: 70 - - - - d3 d2 d1 d0 timeout ms () 510 5 divisionfactor clock mhz () ---------------------------------------------------------------- - = table 10.2 watchdog timeout configuration examples wdt_cr(3:0) division factor timeout values (ms) 5 mhz 10 mhz 20mhz 0000 1 0.1 0.05 0.025 0001 625 62.5 31.25 15.625 0010 1250 125 62.5 31.25 0011 1875 187.5 93.75 46.875 0100 2500 250 125 62.5 0101 3125 312.5 156.25 78.125 0110 3750 375 187.5 93.75 0111 4375 437.5 218.75 109.375 1000 5000 500 250 125 1001 5625 562.5 281.25 140.625 1010 6250 625 312.5 156.25 1011 6875 687.5 343.75 171.875 1100 7500 750 375 187.5 1101 8125 812.5 406.25 203.125 1110 8750 875 437.5 218.75 1111 9375 937.5 468.75 234.375
ST52F500/f503/f504 64/94 11 pwm/timers 11.1 introduction ST52F500/503/504 offers two on-chip pwm/timer peripherals. all ST52F500/503/504 pwm/timers have the same internal structure. the timer consists of a 16-bit counter with a 16-bit programmable prescaler, giving a maximum count of 2 32 (see figure 11.1). each timer has two different working modes, which can be selected by setting the correspondent bit txmod of the pwmx_cr1 configuration register: timer mode and pwm (pulse width modulation) mode. all the timers have autoreload functions; in pwm mode the reload value can be set by the user. each timer output is available on the apposite external pins configured in alternate function and in one of the output modes. pwm/timer 0 can also use external start/stop signals in order to perform input capture and output compare, external reset signal, and external clock to count external events: t0strt, t0res and t0clk pins. in addition, the start/stop and reset signals have configurable polarity (falling or rising edge). remark: to use t0rst, t0str, t0clk external signals the related pins must be configured in alternate function and in one of input modes. for each timer, the contents of the 16-bit counter are incremented on the rising edge of the 16-bit prescaler output (prescout) and it can be read at any instant of the counting phase by accessing the input registers pwmx_count_in_x; the value is stored in two 8-bit registers (msb and lsb) for each pwm/timer. figure 11.1 pwm/timer counter block diagram the input registers couple pwmx_capture_x store the counter value after the last stop signal (only timer mode). the counter value is not stored after a reset signal. the peripheral status can also be read from the input registers (one for each timer). these registers report start/stop, set/reset status, txout signal and the counter overflow flag. this last signal is set after the first eoc and it is reset by a timer reset (internal or external). 11.2 timer mode timer mode is selected writing 0 in the txmod bit. each timer requires three signals: timer clock (tmrclkx), timer reset (txres) and timer start (txstrt) (see figure 11.1). each of these signals can be generated internally, and/or externally only for timer 0, by using t0res, t0strt and t0clk pins. the prescaler output (prescout) increments the counter value on the rising edge. prescout is obtained from the internal clock signal (clkm) or, only for timer0, from the external signal provided on the apposite pin. note: the external clock signal applied on the t0clk pin must have a frequency that is at least two times smaller than the internal master clock. the prescaler output period can be selected by setting the txpresc bits with one of the 17 division factors available. tmrclk frequency is divided by a factor equal to the power of two of the prescaler values (up to 2 16 ). txres resets the content of the 16-bit counter to zero. it is generated by writing 0 in the txres bit of the pwmx_cr1 configuration register and/or it can be driven by the t0res pin if configured (only timer0). bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 14 bit 15 bi t 3 bit 0 bit 1 bit 2 bit 4 bit 5 17 - 1 multiplexer 16-bitprescaler 16-bit counter prescx tmrclkx prescout txres txstrt bit 14 bit 15
ST52F500/f503/f504 65/94 figure 11.2 timer 0 external start/stop mode txstrt signal starts/stops the timer from counting only if the peripherals are configured in timer mode. the timers are started by writing 1 in the txstrt bit of the pwmx_cr1 and are stopped by writing 0. this signal can be generated internally and/or externally by forcing the t0strt pin (only timer0). timer 0 start/stop can be given externally on the t0strt pin. in this case, the t0strt signal allows the user to work in two different configurable modes: n level (time counter): if the t0strt signal is high, the timer starts counting. when the t0strt is low the timer stops counting and the 16-bit current value is stored in the pwm0_count_in_x input registers couple. n edge (period counter): after reset, on the first t0strt rising edge, timer 0 starts counting and at the next rising edge it stops. in this manner the period of an external signal may be measured. the same modes are available for the t0res pin signal. the polarity of the t0srtr start/stop signal can be changed by setting the strpol and respol bits in the int_pol configuration register (01h bit 3 and 4). when these bits are set, the pwm/timer 0 is started/set on the low level or in the falling edge of the signal applied in the pins. the timer output signal, txout, is a signal with a frequency equal to the one of the 16 bit-prescaler output signal, prescoutx, divided by a 16-bit counter set by writing the output register couple pwmx_count_out_x. note: the contents of these registers upgrades the timer counter after it stops counting. since the register couple is written in two steps this can cause side effects. in order to avoid this, the user should write the msb before writing the lsb: actually, the 16-bit value is latched in parallel when the lsb is written. by writing only the lsb (and msb equal to 0), the pwm/timer is used as with an 8 bit counter. there can be two types of txout waveforms: n type 1: txout waveform equal to a square wave with a 50% duty-cycle n type 2: txout waveform equal to a pulse signal with the pulse duration equal to the prescaler output signal. figure 11.3 txout signal types level edge start stop start sta rt stop start 01 1 0 4 4 3 2 reset clock counted value timer output type 1 type 2 prescout*counter
ST52F500/f503/f504 66/94 figure 11.4 pwm mode with reload 11.3 pwm mode the pwm working mode for each timer is obtained by setting the txmod bit of the configuration register pwmx_cr1. the txout signal in pwm mode consists of a signal with a fixed period, whose duty cycle can be modified by the user. the txout period is fixed by setting the 16-bit prescaler bits (txpresc) in the pwmx_cr2 and the 16-bit reload value by writing the relative output registers couple pwmx_reload_x. the 16-bit prescaler divides the master clock clkm by powers of two, determining the maximum length period. reload determines the maximum value that the counter can count before starting a new period. the use of the two 16-bit values allows the txout period to be set with more precision when needed. by setting the reload value the counting resolution decreases. in order to obtain the maximum resolution, reload value should be set to 0ffffh and the period corresponds to the one established by the prescaler value. the value set in the 16-bit counter by writing the counter output registers couple, determines the duty-cycle: when count reaches the counter value the txout signal changes from high to low level. the period of the pwm signal is obtained by using the following formula: t=pwmx - reload * 2 txpresc tmrclkx where txpres equals the value set in the txpresc bits of the pwmx_cr2 configuration register and tmrclkx is the period of the timer clock that drives the prescaler. the duty cycle of the pwm signal is obtained by the following formula: note: the pwm_x_count value must be lower than or equal to the pwm_x_reload value. when it is equal, the txout signal is always at high level. if the output register pwm_x_count is 0, txout signal is always at a low level. by using a 24 mhz clock a pwm frequency that is close to 100 khz can be obtained. the timer0 clock clkm can also be supplied with an external signal, applied on the t0clk pin, which must have a frequency that is at least two times smaller than the internal master clock. note: he timers have to complete the previous counting phase before using a new value of the counter. if the counter value is changed during counting, the new values of the timer counter are only used at the end of the previous counting phase. the counter buffer is written in two steps (one byte per time) and is latched only after the lsb is written. in order to avoid side effects, the user should write the msb before writing the lsb. by only writing the lsb, the pwm/timer is used as with a 8 bit counter. the same mechanism is applied to the two bytes of reload but, differently of the counter it is set immediately. nevertheless, it is recommended that the reload value be written when the timer is stopped in order to avoid incongruence with the counter value. the same recommendation is made when reading the two bytes of the counter: it is performed in two steps, so if the timer is running, the carry of the lsb to the msb can cause the wrong 16-bit value reading. a reload value greater than 1 must always be used. t t 65535 reload value counter value 0 pwm output ton t d cycle t on t -------- pwmxcount pwmxreload ------------------------------------------ ==
ST52F500/f503/f504 67/94 when the timers are in reset status, or when the device is reset, the txout pins goes in threestate. if these outputs are used to drive external devices, it is recommended that the related pins be left in the default configuration (input threestate) or change them in this configuration. in pwm mode the pwm/timers can only be set or reset: start/stop signals do not affect the timers. txres resets the content of the 16-bit counter to zero. it is generated by writing 0 in the corresponding txres bit of the pwmx_cr1 configuration register and/or it can be driven by the t0res pin if it is configured (only timer0). warning: in pwm mode, the txstrt signal must be kept to 1 when the timer is in set state. this can be achieved by writing 1 in the related bit of the configuration register 11.3.1 simultaneous start. the pwm/timers can be started simultaneously when working in pwm mode. the t0sync and t1sync bits in pwm0_cr3 configuration registers mask the reset of each timer; after enabling each single pwm/timer. they are started by putting off the mask with a single writing in the pwm0_cr3 register. simultaneous start is also possible in timer mode. the timers start counting simultaneously, but the output pulses are generated according to the modality configured (square or pulse mode). 11.4 timer interrupts the pwm/timer can be programmed to generate an interrupt request, both on the falling and the rising of the txout signal and when there's a stop signal (external or internal). by using the txies, txier and txief bits of the configuration registers pwmx_cr1, the interrupt sources can be switched on/off. all the interrupt sources may be activated at the same time: sources can be distinguished by reading the pwmx_status input register. the interrupt on the falling edge corresponds to half of a counting period in timer mode when the waveform is set to square wave and to the end of the ton phase in pwm mode. note: when the pwm counter is set to 0 or 65535, the interrupt occurs at the end of each control period. in order to be active, the pwm/timers interrupts must be enabled by writing the interrupt mask register (int_mask) in the configuration register space, bits mskt0 and mskt1. 11.5 pwm/timer 0 register description the following registers are related to the use of the pwm/timer 0. 11.5.1 pwm/timer 0 configuration registers. pwm/timer 0 control register 1 (pwm0_cr1) configuration register 9 (09h) read/write reset value: 0000 0000 (00h) bit 7: t0mod pwm/timer 0 mode 0: timer mode 1: pwm mode bit 6: t0ies interrupt on stop signal enable 0: interrupt disabled 1: interrupt enabled bit 5: t0ief interrupt on t0out falling enable 0: interrupt disabled 1: interrupt enabled bit 4: t0ies interrupt on t0out rising enable 0: interrupt disabled 1: interrupt enabled bit 3: strmod start signal mode 0: start on level 1: start on edge bit 2: t0strt pwm/timer 0 start bit 0: timer 0 stopped 1: timer 0 started bit 1: resmod reset signal mode 0: start on level 1: start on edge bit 0: t0res pwm/timer 0 reset bit 0: pwm/timer 0 reset 1: pwm/timer 0 set 70 t0mod t0ies t0ief t0ier strmod t0strt resmod t0res
ST52F500/f503/f504 68/94 pwm/timer 0 control register 2 (pwm0_cr2) configuration register 10 (0ah) read/write reset value: 0000 0000 (00h) bit 7-6: not used bit 5: t0wav t0out waveform 0: pulse (type2) 1: square (type1) bit 4-0: t0presc pwm/timer 0 prescaler the pwm/timer 0 clock is divided by a factor equal to 2 t0presc . the maximum value allowed for t0presc is 10000 (010h) . pwm/timer 0 control register 3 (pwm0_cr3) configuration register 11 (0bh) read/write reset value: 0000 0000 (00h) bit 7: t0sync pwm/timer 0 set/reset mask 0: set/reset activated 1: set/reset masked bit 6: not used bit 5: t1sync pwm/timer 1 set/reset mask 0: set/reset activated 1: set/reset masked bit 4: t0cks pwm/timer 0 clock source 0: internal clock 1: external clock from t0clk bit 3-2: strsrc pwm/timer 0 start signal source 00: internal from t0strt bit 01: external from t0strt pin 10: both internal and external bit 3-2: ressrc pwm/timer 0 reset source 00: internal from t0strt bit 01: external from t0strt pin 10: both internal and external interrupt polarity register (int_pol) configuration register 1 (01h) read/write reset value: 0000 0000 (00h) bit 7-6: not used bit 5: see lvd registers description bit 4: respol reset signal polarity 0: reset on low level/falling edge 1: reset on high level/rising edge bit 3: strpol start signal polarity 0: start on high level/rising edge 1: start on low level/falling edge bit 2-0: see interrupt registers description 11.5.2 pwm/timer 0 input registers. pwm/timer 0 counter high input register (pwm0_count_in_h) input register 21 (015h) read only reset value: 0000 0000 (00h) bit 7-0: t0ci15-8 pwm/timer 0 counter msb in this register the current value of the timer 0 counter msb can be read. 74 0 - - t0wav t0presc 70 t0sync - t1sync t0cks strsrc ressrc 70 - - lvd_en respol strpol polpb polpa polnmi 70 t0 ci15 t0ci14 t0ci13 t0ci12 t0ci11 t0ci1 0 t0 ci9 t0ci8
ST52F500/f503/f504 69/94 pwm/timer 0 counter low input register (pwm0_count_in_l) input register 22 (016h) read only reset value: 0000 0000 (00h) bit 7-0: t0ci7-0 pwm/timer 0 counter msb in this register the current value of the timer 0 counter lsb can be read. pwm/timer 0 status register (pwm0_status) input register 23 (017h) read only reset value: 0000 0000 (00h) bit 7-4: not used bit 3: t0ovfl pwm / timer 0 counter overflow flag 0: no overflow occurred since last reset 1: overflow occurred bit 2: t0out t0out pin value 0: t0out pin is at logical level 0 1: t0out pin is at logical level 1 bit 2: t0rst reset status 0: pwm/timer 0 is reset 1: pwm/timer 0 is set bit 2: t0sst start status 0: pwm/timer 0 is stopped 1: pwm/timer 0 is running pwm/timer 0 capture high input register (pwm0_capture_h) input register 24 (018h) read only reset value: 0000 0000 (00h) bit 7-0: t0cp15-8 pwm/timer 0 capture msb in this register the counter value after the last stop can be read. pwm/timer 0 capture low input register (pwm0_capture_l) input register 25 (019h) read only reset value: 0000 0000 (00h) bit 7-0: t0cp7-0 pwm/timer 0 capture lsb in this register the counter value after the last stop can be read. 11.5.3 pwm/timer 0 output registers. pwm/timer 0 counter high output register (pwm0_count_out_h) output register 7 (07h) write only reset value: 0000 0000 (00h) bit 7-0: t0co15-8 pwm/timer 0 counter msb this register is used to write the timer 0 counter value (msb). note: this register is latched after writing the lsb part (pwm_count_out_l: see below). for this reason this register must be written before the lsb. pwm/timer 0 counter low output register (pwm0_count_out_l) output register 8 (08h) write only reset value: 0000 0000 (00h) 70 t0ci7 t0ci6 t0ci5 t0ci4 t0 ci3 t0ci2 t0ci1 t0ci0 70 - - - - t0ovfl t0 out t0rst t0sst 70 t0cp15 t0cp14 t0cp13 t0cp12 t0 cp11 t0cp10 t0cp9 t0cp8 70 t0 cp7 t0cp6 t0cp5 t0cp4 t0cp3 t0cp2 t0cp1 t0cp0 70 t0co15 t0co14 t0co13 t0 co12 t0co11 t0co10 t0co9 t0co8 70 t0co7 t0co6 t0 co5 t0co4 t0co3 t0co2 t0co1 t0co0
ST52F500/f503/f504 70/94 bit 7-0: t0co7-0 pwm/timer 0 counter msb this register is used to write the timer 0 counter value (lsb). note: writing this register, the pwm0_count_out_x couple is latched in the internal registers of the peripherals. for this reason, this register should be written after the msb one. pwm/timer 0 reload high output register (pwm0_reload_h) output register 9 (09h) write only reset value: 0000 0000 (00h) bit 7-0: t0rel15-8 pwm/timer 0 reload msb this register is used to write the timer 0 reload value (msb). note: this register is latched after writing the lsb part (pwm0_reload_l: see below). for this reason, this register must be written before the lsb. pwm/timer 0 reload low output register (pwm0_reload_l) output register 8 (08h) write only reset value: 0000 0000 (00h) bit 7-0: t0rel7-0 pwm/timer 0 reload lsb this register is used to write the timer 0 reload value (lsb). note: by writing this register, the pwm0_reload_x couple is latched in the internal registers of the peripherals. for this reason this register should be written after the msb one. 11.6 pwm/timer 1 register description the following registers are related to the use of the pwm/timer 1. 11.6.1 pwm/timer 1 configuration registers. pwm/timer 1 control register 1 (pwm1_cr1) configuration register 12 (0ch) read/write reset value: 0000 0000 (00h) bit 7: t1mod pwm/timer 1 mode 0: timer mode 1: pwm mode bit 6: t1ies interrupt on stop signal enable 0: interrupt disabled 1: interrupt enabled bit 5: t1ief interrupt on t1out falling enable 0: interrupt disabled 1: interrupt enabled bit 4: t1ies interrupt on t1out rising enable 0: interrupt disabled 1: interrupt enabled bit 3: not used bit 2: t1strt pwm/timer 1 start bit 0: timer 0 stopped 1: timer 0 started bit 1: not used bit 0: t1res pwm/timer 1 reset bit 0: pwm/timer 0 reset 1: pwm/timer 0 set 70 t0 rel15 t0rel14 t0rel13 t0rel12 t0rel11 t0rel10 t0rel9 t0rel8 70 t0rel7 t0rel6 t0rel5 t0rel4 t0rel3 t0rel2 t0rel1 t0rel0 70 t0mod t0ies t0ief t0ier - t0strt - t0res
ST52F500/f503/f504 71/94 pwm/timer 1 control register 2 (pwm1_cr2) configuration register 13 (0dh) read/write reset value: 0000 0000 (00h) bit 7-6: not used bit 5: t1wav t1out waveform 0: pulse (type2) 1: square (type1) bit 4-0: t1presc pwm/timer 1 prescaler the pwm/timer 1 clock is divided by a factor equal to 2 t1presc . the maximum value allowed for t1presc is 10000 (010h) . 11.6.2 pwm/timer 1 input registers. pwm/timer 1 counter high input register (pwm1_count_in_h) input register 26 (01ah) read only reset value: 0000 0000 (00h) bit 7-0: t1ci15-8 pwm/timer 1 counter msb in this register the current value of the timer 1 counter msb can be read. pwm/timer 1 counter low input register (pwm1_count_in_l) input register 27 (01bh) read only reset value: 0000 0000 (00h) bit 7-0: t1ci7-0 pwm/timer 1 counter msb in this register the current value of the timer 0 counter lsb can be read. pwm/timer 1 status register (pwm1_status) input register 28 (01ch) read only reset value: 0000 0000 (00h) bit 7-4: not used bit 3: t1ovfl pwm / timer 0 counter overflow flag 0: no overflow occurred since last reset 1: overflow occurred bit 2: t1out t0out pin value 0: t0out pin is at logical level 0 1: t0out pin is at logical level 1 bit 2: t1rst reset status 0: pwm/timer 0 is reset 1: pwm/timer 0 is set bit 2: t1sst start status 0: pwm/timer 0 is stopped 1: pwm/timer 0 is running pwm/timer 1 capture high input register (pwm1_capture_h) input register 29 (01dh) read only reset value: 0000 0000 (00h) bit 7-0: t1cp15-8 pwm/timer 1 capture msb in this register the counter value after the last stop can be read. pwm/timer 1 capture low input register (pwm1_capture_l) input register 30 (01eh) read only 74 0 - - t1wav t1presc 70 t1ci15 t1ci14 t1ci13 t1ci1 2 t1ci11 t1 ci10 t1ci9 t1ci8 70 t1ci7 t1ci6 t1ci5 t1ci4 t1 ci3 t1ci2 t1ci1 t1ci0 70 - - - - t1ovfl t1out t1rst t1sst 70 t1cp15 t1cp14 t1cp13 t1cp12 t1cp11 t1cp10 t1cp9 t1cp8
ST52F500/f503/f504 72/94 reset value: 0000 0000 (00h) bit 7-0: t1cp7-0 pwm/timer 1 capture lsb in this register the counter value after the last stop can be read. 11.6.3 pwm/timer 1 output registers. pwm/timer 1 counter high output register (pwm1_count_out_h) output register 11 (0bh) write only reset value: 0000 0000 (00h) bit 7-0: t1co15-8 pwm/timer 1 counter msb this register is used to write the timer 1 counter value (msb). note: this register is latched after writing the lsb part (pwm1_count_out_l: see below). for this reason, this register must be written before the lsb. pwm/timer 1 counter low output register (pwm1_count_out_l) output register 12 (0ch) write only reset value: 0000 0000 (00h) bit 7-0: t1co7-0 pwm/timer 0 counter msb this register is used to write the timer 1 counter value (lsb). note: by writing this register, the pwm1_count_out_x couple is latched in the internal registers of the peripherals. for this reason this register should be written after the msb one. pwm/timer 1 reload high output register (pwm1_reload_h) output register 13 (0dh) write only reset value: 0000 0000 (00h) bit 7-0: t1rel15-8 pwm/timer 0 reload msb this register is used to write the timer 1 reload value (msb). note: this register is latched after writing the lsb part (pwm1_reload_l: see below). for this reason, this register must be written before the lsb. pwm/timer 1 reload low output register (pwm0_reload_l) output register 14 (0eh) write only reset value: 0000 0000 (00h) bit 7-0: t1rel7-0 pwm/timer 1 reload lsb this register is used to write the timer 1 reload value (lsb). note: by writing this register, the pwm1_reload_x couple is latched in the internal registers of the peripherals. for this reason, this register should be written after the msb one. 70 t1cp7 t1cp6 t1cp5 t1cp4 t1cp3 t1cp2 t1cp1 t1cp0 70 t1co15 t1 co14 t1co13 t1co12 t1co11 t1co10 t1co9 t1 co8 70 t1co7 t1co6 t1co5 t1co4 t1co3 t1co2 t1co1 t1 co0 70 t1rel15 t1rel14 t1rel13 t1rel12 t1rel11 t1rel10 t1rel9 t1 rel8 70 t1rel7 t1rel6 t1rel5 t1rel4 t1rel3 t1rel2 t1rel1 t01rel0
ST52F500/f503/f504 73/94 12 i 2 c bus interface (i 2 c) 12.1 introduction the i 2 c bus interface serves as an interface between the microcontroller and the serial i 2 cbus, providing both multimaster and slave functions and controls all i 2 c bus-specific sequencing, protocol, arbitration and timing. the i 2 bus interface supports fast i 2 c mode (400khz). 12.2 main features n parallel-bus/i 2 c protocol converter n multi-master capability n 7-bit/10-bit addressing n transmitter/receiver flag n end-of-byte transmission flag n transfer problem detection i 2 c master features: n clock generation n i 2 c bus busy flag n arbitration lost flag n end of byte transmission flag n transmitter/receiver flag n start bit detection flag n start and stop generation i 2 c slave features: n stop bit detection n i 2 c bus busy flag n detection of misplaced start or stop condition n programmable i 2 c address detection n transfer problem detection n end-of-byte transmission flag n transmitter/receiver flag figure 12.1 i 2 c bus protocol 12.3 general description in addition to receiving and transmitting data, this interface converts it from serial to parallel format and vice versa, using either an interrupt or polled handshake. the interrupts are enabled or disabled via software. the interface is connected to the i 2 c bus by a data pin (sda) and by a clock pin (scl). the interface can be connected both with a standard i 2 c bus and a fast i 2 c bus. this selection is made via software. 12.3.1 mode selection. the interface can operate in the following four modes: slave transmitter/receiver master transmitter/receiver by default, it operates in slave mode. the interface automatically switches from slave to master after it generates a start condition and from master to slave in case of arbitration loss or a stop generation, providing multi-master capability. 12.3.2 communication flow. in master mode, communication flow initiates data transfer and generates the clock signal. a serial data transfer always begins with a start condition and ends with a stop condition. both start and stop conditions are generated in master mode by software. in slave mode the interface is capable of recognizing its own address (7 or 10-bit) and the general call address. the general call address detection may be enabled or disabled by software. data and addresses are transferred as 8-bit bytes, (msb first). the first byte(s) follow the start condition is the address (one in 7-bit mode, two in 10-bit mode), which is always transmitted in master mode.a 9th clock pulse follows the 8 clock cycles of a byte transfer, during which the receiver must send an acknowledge bit to the transmitter. refer to figure 12.1. scl sda 12 8 9 msb ack stop start condition condition
ST52F500/f503/f504 74/94 acknowledge may be enabled and disabled via software. the i 2 c interface address and/or general call address can be selected via software. the speed of the i 2 c interface may be selected between standard (0-100khz) and fast i 2 c (100- 400khz). 12.3.3 sda/scl line control. transmitter mode : the interface holds the clock line low before transmission, in order to wait for the microcontroller to write the byte in the data register. receiver mode : the interface holds the clock line low after reception to wait for the microcontroller to read the byte in the data register. scl frequency is controlled by a programmable clock divider which depends on the i 2 c bus mode. when the i 2 c cell is enabled, the sda and scl pins must be configured as floating open-drain i/o. the value of the external pull-up resistance used depends on the application. 12.4 functional description by default the i 2 c interface operates in slave mode (m/sl bit is cleared) except when it initiates a transmit or receive sequence. first, the interface frequency must be configured using the related bits of the configuration registers. 12.4.1 slave mode. as soon as a start condition is detected, the address is received from the sda line and sent to the shift register; then it is compared with the address of the interface or the general call address (if selected by software). figure 12.2 i 2 c interface block diagram data register data shift register comparator own address registe r (oar) clock control register (i2c_ccr) status register 1 (i2c_sr1) control register (i2c_cr) sda scl control logic status register 2 (i2c_sr2) interrupt clock control data control scl sda
ST52F500/f503/f504 75/94 note: in 10-bit addressing mode, the comparison includes the header sequence (11110xx0) and the two most significant bits of the address. header matched (10-bit mode only): the interface generates an acknowledgement pulse if the ack bit is set. address not matched : the interface ignores it and waits for another start condition. address matched : the interface generates in sequence: acknowledge pulse if the ack bit is set. evf and adsl bits are set with an interrupt if the ite bit is set. afterwards, the interface waits for the i2c_sr1 register to be read, holding the scl line low (see figure 12.3 transfer sequencing ev1). next, in 7-bit mode read the i2c_in register to determine from the least significant bit (data direction bit) if the slave must enter receiver or transmitter mode. in 10-bit mode, after receiving the address sequence the slave is always in receive mode. it will enter transmit mode on receiving a repeated start condition followed by the header sequence with matching address bits and the least significant bit set (11110xx1). slave receiver following reception of the address and after the i2c_sr1 register has been read, the slave receives bytes from the sda line into the i2c_in register via the internal shift register. after each byte, the interface generates the following in sequence: acknowledge pulse if the ack bit is set evf and btf bits are set with an interrupt if the ite bit is set. afterwards, the interface waits for the i2c_sr1 register to be read followed by a read of the i2c_in register, holding the scl line low (see figure 12.3 transfer sequencing ev2). slave transmitter following the address reception and after the i2c_sr1 register has been read, the slave sends bytes from the i2c_out register to the sda line via the internal shift register. the slave waits for a read of the i2c_sr1 register followed by a write in the i2c_out register, holding the scl line low (see figure 12.3 transfer sequencing ev3). when the acknowledge pulse is received: the evf and btf bits are set by hardware with an interrupt if the ite bit is set. closing slave communication after the last data byte is transferred a stop condition is generated by the master. the interface detects this condition and sets: evf and stopf bits with an interrupt if the ite bit is set. afterwards, the interface waits for a read of the i2c_sr2 register (see figure 12.3 transfer sequencing ev4). error cases berr : detection of a stop or a start condition during a byte transfer. in this case, the evf and the berr bits are set with an interrupt if the ite bit is set. if it is a stop then the interface discards the data, released the lines and waits for another start condition. if it is a start then the interface discards the data and waits for the next slave address on the bus. af : detection of a non-acknowledge bit. in this case, the evf and af bits are set with an inter- rupt if the ite bit is set. note: in both cases, the scl line is not held low; however, sda line can remain low due to possible ?0? bits transmitted last. at this point, both lines must be released by software. how to release the sda / scl lines set and subsequently clear the stop bit while btf is set. the sda/scl lines are released after the current byte is transferred. 12.4.2 master mode. to switch from default slave mode to master mode a start condition generation is needed. start condition setting the start bit while the busy bit is cleared causes the interface to switch to master mode (m/sl bit set) and generates a start condition. once the start condition is sent: the evf and sb bits are set by hardware with an interrupt if the ite bit is set. afterwards, the master waits for a read of the i2c_sr1 register followed by a write in the i2c_out register with the slave address, holding the scl line low (see figure 12.3 transfer sequencing ev5).
ST52F500/f503/f504 76/94 slave address transmission at this point, the slave address is sent to the sda line via the internal shift register. in 7-bit addressing mode, one address byte is sent. in 10-bit addressing mode, sending the first byte including the header sequence causes the following event: the evf bit is set by hardware with interrupt generation if the ite bit is set. afterwards, the master waits for a read of the i2c_sr1 register followed by a write in the i2c_out register, holding the scl line low (see figure 12.3 transfer sequencing ev9). the second address byte is sent by the interface. after completion of this transfer (and acknowledge from the slave if the ack bit is set): the evf bit is set by hardware with interrupt generation if the ite bit is set. afterwards, the master waits for a read of the i2c_sr1 register followed by a write in the i2c_cr register (for example set pe bit), holding the scl line low (see figure 12.3 transfer sequencing ev6). next, the master must enter receiver or transmitter mode. note: in 10-bit addressing mode, in order to switch the master to receiver mode, software must generate a repeated start condition and resend the header sequence with the least significant bit set (11110xx1). master receiver following the address transmission and after i2c_sr1 and i2c_cr registers have been accessed, the master receives bytes from the sda line into the i2c_in register via the internal shift register. after each byte the interface generates in sequence: acknowledge pulse if the ack bit is set evfand btf bits are set by hardware with an in- terrupt if the ite bit is set. afterwards, the interface waits for a read of the i2c_sr1 register followed by a read of the i2c_in register, holding the scl line low (see figure 12.3 transfer sequencing ev7). in order to close the communication: before reading the last byte from the i2c_in register, set the stop bit to generate the stop condition. the interface automatically goes back to slave mode (m/sl bit cleared). note: in order to generate the non-acknowledge pulse after the last data byte received, the ack bit must be cleared just before reading the second last data byte. master transmitter following the address transmission and after the i2c_sr1 register has been read, the master sends bytes from the i2c_out register to the sda line via the internal shift register. the master waits for a read of the i2c_sr1 register followed by a write in the i2c_out register, holding the scl line low (see figure 12.3 transfer sequencing ev8). when the acknowledge bit is received, the interface sets: evf and btf bits with an interrupt if the ite bit is set. in order to close the communication: after writing the last byte to the i2c_out register, set the stop bit to generate the stop condition. the interface automatically returns to slave mode (m/ sl bit cleared). error cases berr : detection of a stop or a start condition during a byte transfer. in this case, the evf and berr bits are set by hardware with an interrupt if ite is set. af : detection of a non-acknowledge bit. in this case, the evf and af bits are set by hardware with an interrupt if the ite bit is set. to resume, set the start or stop bit. arlo : detection of an arbitration lost condition. in this case the arlo bit is set by hardware (with an interrupt if the ite bit is set and the in- terface automatically goes back to slave mode (the m/sl bit is cleared). note: in all these cases, the scl line is not held low; however, the sda line can remain low due to possible ?0? bits transmitted last. both lines must be released via software.
ST52F500/f503/f504 77/94 figure 12.3 tranfer sequencing 7-bit slave receiver: 7-bit slave transmitter: 7-bit master receiver: 7-bit master transmitter: 10-bit slave receiver: 10-bit slave transmitter: 10-bit master transmitter: 10-bit master receiver: legend: s=start, p=stop, a=acknowledge, na=non-acknowledge evx=event (with interrupt if ite=1) ev1: evf=1, adsl=1, cleared by reading i2c_sr1 register. ev2: evf=1, btf=1, cleared by reading i2c_sr1 register followed by reading i2c_in register. ev3: evf=1, btf=1, cleared by reading i2c_sr1 register followed by writing i2c_out register. ev3-1: evf=1, af=1, btf=1; af is cleared by reading i2c_sr1. btf is cleared by releasing the lines (stop=1, stop=0) or by writing i2c_out register (i2c_out=ffh). note: if lines are released by stop=1, stop=0, the subsequent ev4 is not seen. ev4: evf=1, stopf=1, cleared by reading i2c_sr2 register. ev5: evf=1, sb=1, cleared by reading i2c_sr1 register followed by writing i2c_out register. ev6: evf=1, cleared by reading i2c_sr1 register followed by writing i2c_cr (for example pe=1 ev7: evf=1, btf=1, cleared by reading i2c_sr1 register followed by reading i2c_iin register. ev8: evf=1, btf=1, cleared by reading i2c_sr1 register followed by writing i2c_out register. ev9: evf=1, add10=1, cleared by reading i2c_sr1 register followed by writing i2c_out registe s address a data1 a data2 a ..... datan a p ev1 ev2 ev2 ev2 ev4 s address a data1 a data2 a ..... datan na p ev1 ev3 ev3 ev3 ev3-1 ev4 s address a data1 a data2 a ..... datan na p ev5 ev6 ev7 ev7 ev7 s address a data1 a data2 a ..... datan a p ev5 ev6 ev8 ev8 ev8 ev8 s header a address a data1 a ..... datan a p ev1 ev2 ev2 ev4 s r header a data1 a .... . datan a p ev1 ev3 ev3 ev3-1 ev4 s header a address a data1 a ..... datan a p ev5 ev9 ev6 ev8 ev8 ev8 s r header a data1 a ..... datan a p ev5 ev6 ev7 ev7
ST52F500/f503/f504 78/94 figure 12.4 event flags and interrupt generation note: the i 2 c interrupt events are connected to the same interrupt vector. they generate an interrupt if the corresponding enable control bit (ite) is set and the interrupt mask bit (mski2c) in the int_mask configuration register is unmasked (set to 1, see interrupts chapter). add10 btf adsl sb af stopf evf interrupt ite * * evf can also be set by ev6 or an error from the i2c_sr2 register. arlo berr interrupt event event flag enable control bit exit from wait exit from halt 10-bit address sent event (master mode) add10 ite yes no end of byte transfer event btf yes no address matched event (slave mode) adsel yes no start bit generation event (master mode) sb yes no acknowledge failure event af yes no stop detection event (slave mode) stopf yes no arbitration lost event (multimaster configuration) arlo yes no bus error event berr yes no
ST52F500/f503/f504 79/94 12.5 register description in the following sections describe the registers used by the i 2 c interface are described. 12.5.1 i 2 c interface configuration registers. i 2 c control register (i2c_cr) configuration register 16 (010h) read/write reset value: 0000 0000 (00h) bit 7-6: not used bit 5: pe peripheral enable. this bit is set and cleared by software 0: peripheral disabled 1: peripheral enabled notes: when pe=0, all the bits of the i2c_cr register and the sr register except the stop bit are reset. all outputs are released while pe=0 when pe=1, the corresponding i/o pins are se- lected by hardware as alternate functions. to enable the i 2 c interface, write the i2c_cr register twice with pe=1 as the first write only activates the interface (only pe is set). bit 4: engc enable general call this bit is set and cleared by software. it is also cleared by hardware when the interface is disabled (pe=0). 0: general call disabled 1: general call enabled note: the 00h general call address is acknowledged (01h ignored). bit 3: start generation of a start condition this bit is set and cleared by software. it is also cleared by hardware when the interface is disabled (pe=0) or when the start condition is sent (with interrupt generation if ite=1). in master mode 0: no start generation 1: repeated start generation in slave mode 0: no start generation 1: start generation when the bus is free bit 2: ack acknowledge enable this bit is set and cleared by software. it is also cleared by hardware when the interface is disabled (pe=0). 0: no acknowledge returned 1: acknowledge returned after an address byte or a data byte is received bit 1: stop reset signal mode this bit is set and cleared by software. it is also cleared by hardware in master mode. note: this bit is not cleared when the interface is disabled (pe=0). in master mode 0: no stop generation 1: stop generation after the current byte transfer or after the current start condition is sent. the stop bit is cleared by hardware when the stop condition is sent. in slave mode 0: no start generation 1: release the scl and sda lines after the current byte transfer (btf=1). in this mode the stop bit has to be cleared by software. bit 0: ite interrupt enable 0: interrupt disabled 1: interrupt enabled i 2 c clock control register (i2c_ccr) configuration register 17 (011h) read/write reset value: 0000 0000 (00h) bit 7: fm/sm fast/standard i 2 c mode. this bit is set and cleared by software. it is not cleared when the interface is disabled (pe=0). 70 - - pe engc start ack stop ite 70 fm/sm cc6 cc5 cc4 cc3 cc2 cc1 cc0
ST52F500/f503/f504 80/94 0: standard i 2 c mode 1: fast i 2 c mode bit 6-0: cc6-cc0 7-bit clock divider these bits select the speed of the bus (f scl ) depending on the i 2 c mode. they are not cleared when the interface is disabled (pe=0). standard mode (fm/sm=0): f scl <= 100khz f scl =f cpu /(3x([cc6..cc0]+9)) fast mode (fm/sm=1): f scl > 100khz f scl =f cpu /(2x([cc6..cc0]+7)) warning: for safety reason, cc6-cc0 bits must be configured with a value >= 3 for the standard mode and >=2 for the fast mode. i 2 c own address register 1 (i2c_oar1) configuration register 18 (012h) read/write reset value: 0000 0000 (00h) 7-bit addressing mode bit 7-1: add7-add1 interface address. these bits define the i 2 c bus address of the interface. they are not cleared when the interface is disabled (pe=0). bit 0: add0 address direction bit. this bit is adon't careo, the interface acknowledges either 0 or 1. it is not cleared when the interface is disabled (pe=0). note: address 01h is always ignored. 10-bit addressing mode bit 7-0: add7-add0 interface address. these are the least significant bits of the i 2 c bus address of the interface. they are not cleared when the interface is disabled (pe=0). i 2 c own address register 2 (i2c_oar2) configuration register 19 (013h) read/write reset value: 0000 0000 (00h) bit 7-3: not used bit 7-1: add8-add8 interface address. these are the most significant bits of th i 2 c bus address of the interface (10-bit mode only). they are not cleared when the interface is disabled (pe=0). bit 0: reserved 12.5.2 i 2 c interface input registers. i 2 c data input register (i2c_in) input register 6 (06h) read only reset value: 0000 0000 (00h) bit 7-0: i2cdi7-i2cdi0 received data. these bits contain the byte to be received from the bus in receiver mode: the first data byte is received automatically in the i2c_in register using the least significant bit of the address. then, the next data bytes are received one by one after reading the i2c_in register. i 2 c status register 1 (i2c_sr1) input register 7 (07h) read only reset value: 0000 0000 (00h) 70 add7 add6 add5 add4 add3 add2 add1 add0 720 - - - - - add9 add8 - 70 i2cdi7 i2cdi6 i2cdi5 i2cdi4 i2cdi3 i2cdi2 i2cdi1 i2cdi0 70 evf add10 tra busy btf adsl m/sl sb
ST52F500/f503/f504 81/94 bit 7: evf event flag this bit is set by hardware as soon as an event occurs. it is cleared by software reading i2c_sr2 register in case of error event or as described in figure 12.3. it is also cleared by hardware when the interface is disabled (pe=0). 0: no event 1: one of the following events has occurred: btf=1 (byte received or transmitted) adsl=1 (address matched in slave mode while ack=1) sb=1 (start condition generated in mas- ter mode) af=1 (no acknowledge received after byte transmission) stopf=1 (stop condition detected in slave mode) arlo=1 (arbitration lost in master mode) berr=1 (bus error, misplaced start or stop condition detected) address byte successfully transmitted in master mode. bit 6: add10 10 bit addressing in master mode this bit is set by hardware when the master has sent the first byte in 10-bit address mode. it is cleared by software reading i2c_sr2 register followed by a write in the i2c_out register of the second address byte. it is also cleared by hardware when the peripheral is disabled (pe=0). 0: no add10 event occurred 1: the master has sent the first address byte bit 5: tra transmitter/receiver when btf is set, tra=1 if a data byte has been transmitted. it is cleared automatically when btf is cleared. it is also cleared by hardware after detection of stop condition (stopf=1), loss of bus arbitration (arlo=1) or when the interface is disabled (pe=0). 0: data byte received (if btf=1) 1: data byte transmitted bit 4: busy bus busy this bit is set by hardware on detection of a start condition and cleared by hardware on detection of a stop condition. it indicates a communication in progress on the bus. this information is still updated when the interface is disabled (pe=0). 0: no communication on the bus 1: communication ongoing on the bus bit 3: btf byte transfer finished this bit is set by hardware as soon as a byte is correctly received or transmitted with interrupt generation if ite=1. it is cleared by software reading i2c_sr1 register followed by a read of i2c_in or write of i2c_out registers. it is also cleared by hardware when the interface is disabled (pe=0). following a byte transmission, this bit is set after reception of the acknowledge clock pulse. in case an address byte is sent, this bit is set only after the ev6 event (see figure 12.3). btf is cleared by reading i2c_sr1 register followed by writing the next byte in i2c_out register. following a byte reception, this bit is set after transmission of the acknowledge clock pulse if ack=1. btf is cleared by reading i2c_sr1 register followed by reading the byte from i2c_in register. the scl line is held low while btf=1. 0: byte transfer not done 1: byte transfer succeeded bit 2: adsl address matched (slave mode) this bit is set by hardware as soon as the slave address received matched with the oar register content or a general call is recognized. an interrupt is generated if ite=1. it is cleared by software reading i2c_sr1 register or by hardware when the interface is disabled (pe=0). the scl line is held low while adsl=1. 0: address mismatched or not received 1: received address matched bit 1: m/sl master/slave this bit is set by hardware as soon as the interface is in master mode (writing start=1). it is cleared by hardware after detecting a stop condition on the bus or a loss of arbitration (arlo=1). it is also cleared when the interface is disabled (pe=0). 0: slave mode 1: master mode bit 0: sb start bit (master mode) this bit is set by hardware as soon as the start condition is generated (following a write
ST52F500/f503/f504 82/94 start=1). an interrupt is generated if ite=1. it is cleared by software reading i2c_sr1 register followed by writing the address byte in i2c_out register. it is also cleared by hardware when the interface is disabled (pe=0). 0: no start condition 1: start condition generated i 2 c status register 2 (i2c_sr2) input register 8 (08h) read only reset value: 0000 0000 (00h) bit 7-5: reserved. bit 4: af acknowledge failure . this bit is set by hardware when an acknowledge is returned. an interrupt is generated if ite=1. it is cleared by software reading the i2c_sr2 register or by hardware when the interface is disabled (pe=0). the scl line is not held low while af=1. 0: no acknowledge failure 1: acknowledge failure bit 3: stopf stop detection (slave mode). this bit is set by hardware when a stop condition is detected on the bus after an acknowledge (if ack=1). an interrupt is generated if ite=1. it is cleared by software reading i2c_sr2 register or by hardware when the interface is disabled (pe=0). the scl line is not held low while stopf=1. 0: no stop condition detected 1: stop condition detected bit 2: arlo arbitration lost . this bit is set by hardware when the interface loses the arbitration of the bus to another master. an interrupt is generated if ite=1. it is cleared by software reading i2c_sr2 register or by hardware when the interface is disabled (pe=0). after an arlo event the interface switches back automatically to slave mode (m/sl=0). the scl line is not held low while arlo=1. 0: no arbitration lost detected 1: arbitration lost detected bit 1: berr bus error. this bit is set by hardware when the interface detects a misplaced start or stop condition. an interrupt is generated if ite=1. it is cleared by software reading i2c_sr2 register or by hardware when the interface is disabled (pe=0). the scl line is not held low while berr=1. 0: no misplaced start or stop condition 1: misplaced start or stop condition bit 0: gcal general call (slave mode). this bit is set by hardware when a general call address is detected on the bus while engc=1. it is cleared by hardware detecting a stop condition (stopf=1) or when the interface is disabled (pe=0). 0: no general call address detected on bus 1: general call address detected on bus 12.5.3 i 2 c interface output registers. i 2 c data output register (i2c_out) output register 6 (06h) read only reset value: 0000 0000 (00h) bit 7-0: i2cdo7-i2cdo0 data to be transmitted. these bits contain the byte to be transmitted in the bus in transmitter mode: byte transmission start automatically when the software writes in the i2c_out register. 70 - - - af stopf arlo berr gcal 70 i2cdo7 i2cdo6 i2cdo5 i2cdo4 i2cdo3 i2cdo2 i2cdo1 i2cdo0
ST52F500/f503/f504 83/94 13 serial peripheral interface (spi) 13.1 introduction the serial peripheral interface (spi) allows full- duplex, synchronous, serial communication with external devices. an spi system may consist of a master, one or more slaves, or a system, in which devices may be either masters or slaves. spi is normally used for communication between the icu and external peripherals or another icu. refer to the pin description section in this datasheet for the device-specific pin-out. 13.2 main features n full duplex, three-wire synchronous transfers n master or slave operation n four master mode frequencies n maximum slave mode frequency = ckm/4. n four programmable master bit rates n programmable clock polarity and phase n end of transfer interrupt flag n write collision flag protection n master mode fault protection capability. 13.3 general description spi is connected to external devices through 4 alternate pins: miso: master in / slave out pin mosi: master out / slave in pin sck: serial clock pin ss: slave select pin (if not done through soft- ware) figure 13.1 spi master slave a basic example of interconnections between a single master and a single slave is illustrated in figure 13.1 the mosi pins are connected together as the miso pins. in this manner, data is transferred serially between master and slave (most significant bit first). when the master device transmits data to a slave device via the mosi pin, the slave device responds by sending data to the master device via the miso pin. this implies full duplex transmission with both data out and data in synchronized with the same clock signal (which is provided by the master device via the sck pin). the transmitted byte is replaced by the byte received and eliminates the need for separate transmit-empty and receiver-full bits. a status flag is used to indicate that the i/o operation is complete. four possible data/clock timing relationships may be chosen (see figure 13.4), but master and slave must be programmed with the same timing mode. 13.4 functional description figure 13.2 shows the serial peripheral interface (spi) block diagram. this interface contains 3 dedicated registers: a control register (spi_cr) a status register (spi_status_cr) a data register for transmission (spi_out) a data register for reception (spi_out) 13.4.1 master configuration. in a master configuration, the serial clock is generated on the sck pin. 8-bit shift register spi clock generator 8-bit shift register miso mosi mosi miso sck sck slave master ss ss +5v msbit lsbit msbit lsbit
ST52F500/f503/f504 84/94 figure 13.2 serial peripheral interface block diagram procedure select the spr0, spr1 and spr2 bits to define the serial clock baud rate (see spi_cr register). select the cpol and cpha bits to define one of the four relationships between the data transfer and the serial clock (see figure 13.4). the ss pin must be connected to a high level signal during the complete byte transmit se- quence. the mstr and spe bits must be set (they re- main set only if the ss pin is connected to a high level signal). in this configuration the mosi pin is a data output and to the miso pin is a data input. transmit sequence transmit sequence begins when a byte is written in the spi_out register. the data byte is loaded in parallel into the 8-bit shift register (from the internal bus) during a write cycle and then shifted out serially to the mosi pin most significant bit first. when data transfer is complete: the spif bit is set by hardware an interrupt is generated if the spie bit is set. during the last clock cycle the spif bit is set, a copy of the data byte received in the shift register is moved to a buffer. when the spi_in register is read, the spi peripheral returns this buffered value. clearing the spif bit is performed by the following software sequence: 1. an access to the spi_status_cr register while the spif bit is set 2. a read to the spi_in register. note: while the spif bit is set, all writes to the spi_out register are inhibited until the spi_status_cr register is read. spi_in read buffer 8-bit shift register write read internal bus spi spie spe mstr cpha spr0 spr1 cpol spif wcol modf serial clock generator mosi miso ss sck control state spi_cr spi_status_cr - it request master control spr2 or ssi ssm sod spi_out
ST52F500/f503/f504 85/94 13.4.2 slave configuration. in slave configuration, the serial clock is received on the sck pin from the master device. the value of the spr0, spr1 and spr2 bits is not used for data transfer. procedure for correct data transfer, the slave device must be in the same timing mode as the master de- vice (cpol and cpha bits). see figure 13.4. the ss pin must be connected to a low level sig- nal during the complete byte transmit sequence. clear the mstr bit and set the spe bit to assign the pins to alternate function. in this configuration the mosi pin is a data input and the miso pin is a data output. transmit sequence the data byte is loaded into the 8-bit shift register (from the internal bus) during a write cycle and then shifted out serially to the miso pin most significant bit first. the transmit sequence begins when the slave device receives the clock signal and the most significant bit of the data on its mosi pin. when data transfer is complete: the spif bit is set by hardware an interrupt is generated if spie bit is set. during the last clock cycle the spif bit is set, a copy of the data byte received in the shift register is moved to a buffer. when the spi_in register is read, the spi peripheral returns the buffer value. the spif bit is cleared by the following software sequence: 1. an access to the spi_status_cr register while the spif bit is set. 2. a read to the spi_in register. note: while the spif bit is set, all writes to the spi_out register are inhibited until the spi_status_cr register is read. the spif bit can be cleared during a second transmission; however, it must be cleared before the second spif bit in order to prevent an overrun condition (see section 13.4.6). depending on the cpha bit, the ss pin has to be set to write to the spi_out register between each data byte transfer to avoid a write collision (see section 13.4.4). 13.4.3 data transfer format. during an spi transfer, data is simultaneously transmitted (shifted out serially) and received (shifted in serially). the serial clock is used to synchronize data transfer during a sequence of eight clock pulses. the ss pin allows individual selection of a slave device; the other slave devices that are not selected do not interfere with spi transfer. clock phase and clock polarity four possible timing relationships may be chosen by software, using the cpol and cpha bits. the cpol (clock polarity) bit controls the steady state value of the clock when data isn't being transferred. this bit affects both master and slave modes. the combination between the cpol and cpha (clock phase) bits select the data capture clock edge. figure 13.4, shows an spi transfer with the four combinations of the cpha and cpol bits. the diagram may be interpreted as a master or slave timing diagram where the sck pin, the miso pin, the mosi pin are directly connected between the master and the slave device. the ss pin is the slave device select input and can be driven by the master device. the master device applies data to its mosi pin- clock edge before the capture clock edge. cpha bit is set the second edge on the sck pin (falling edge if the cpol bit is reset, rising edge if the cpol bit is set) is the msbit capture strobe. data is latched on the occurrence of the second clock transition. a write collision should not occur even if the ss pin stays low during a transfer of several bytes (see figure 13.3). cpha bit is reset the first edge on the sck pin (falling edge if cpol bit is set, rising edge if cpol bit is reset) is the msbit capture strobe. data is latched on the occurrence of the first clock transition. the ss pin must be toggled high and low between each byte transmitted (see figure 13.3). in order to protect the transmission from a write collision a low value on the ss pin of a slave device freezes the data in its spi_out register and does not allow it to be altered. therefore, the ss pin must be high to write a new data byte in the spi_out without producing a write collision. 13.4.4 write collision error.
ST52F500/f503/f504 86/94 a write collision occurs when the software tries to write to the spi_out register while a data transfer is taking place with an external device. when this occurs, the transfer continues uninterrupted; and the software writing will be unsuccessful. write collisions can occur both in master and slave mode. note: a aread collisiono will never occur since the data byte received is placed in a buffer, in which access is always synchronous with the icu operation. in slave mode when the cpha bit is set: the slave device will receive a clock (sck) edge prior to the latch of the first data transfer. this first clock edge will freeze the data in the slave device spi_out register and output the msbit on to the external miso pin of the slave device. the ss pin low state enables the slave device, but the output of the msbit onto the miso pin does not take place until the first data transfer clock edge occurs. when the cpha bit is reset: data is latched on the occurrence of the first clock transition. the slave device doesn't have a way of knowing when that transition will occur; therefore, the slave device collision occurs when software attempts to write the spi_out register after its ss pin has been pulled low. for this reason, the ss pin must be high, between each data byte transfer, in order to allow the cpu to write in the spi_out register without generating a write collision. in master mode collision in the master device is defined as a write of the spi_out register, while the internal serial clock (sck) is in the process of transfer. the ss pin signal must always be high on the master device. figure 13.3 chpa/ss timing diagram wcol bit the wcol bit in the spi_status_cr register is set if a write collision occurs. no spi interrupt is generated when the wcol bit is set (the wcol bit is a status flag only). the wcol bit is cleared by a software sequence (see section 13.5). 13.4.5 master mode fault. master mode fault occurs when the master device has its ss pin pulled low, then the modf bit is set. master mode fault affects the spi peripheral in the following ways: the modf bit is set and an spi interrupt is generated if the spie bit is set. the spe bit is reset. this blocks all output from the device and disables the spi peripheral. the mstr bit is reset, forcing the device into slave mode. clearing the modf bit is done through a software sequence: 1. a read or write access to the spi_status_cr register while the modf bit is set. 2. a write to the spi_cr register. note: to avoid any multiple slave conflicts in the case of a system comprising several mcus, the ss pin must be pulled high during the clearing sequence of the modf bit. the spe and mstr bits may be restored to their original state during or after this clearing sequence. hardware does not allow the user to set the spe and mstr bits, while the modf bit is set (except in the modf bit clearing sequence). in a slave device the modf bit can't be set, but in a multi master configuration the device can be in slave mode with this modf bit set. the modf bit indicates that there might have been a multi-master conflict for system control and allows a proper exit from system operation to a mosi/miso master ss slave ss (cpha=0) slave ss (cpha=1) byte 1 byte 2 byte 3
ST52F500/f503/f504 87/94 reset or default system state using an interrupt routine. figure 13.4 data clock timing diagram cpol = 1 cpol = 0 msbit bit 6 bit 5 msbit bit 6 bit 5 miso (from master) mosi (from slave) ss (to slave) capture strobe c cpol = 1 cpol = 0 msbit bit 6 bit 5 msbit bit 6 bit 5 miso (from master) mosi ss (to slave) capture strobe c note: this figure should not be used as a repla refer to the electrical characteristics chapter. (from slave)
ST52F500/f503/f504 88/94 figure 13.5 clearing the wcol bit (write collision flag) software sequence 13.4.6 overrun condition. an overrun condition occurs when the master device has sent several data bytes and the slave device hasn't cleared the spif bit issued from the previous data byte transmitted. in this case, the receiver buffer contains the byte sent after the spif bit was last cleared. a read to the spi_in register returns this byte. all other bytes are lost. this condition is not detected by the spi peripheral. 13.4.7 single master and multimaster configu- rations. there are two types of spi systems: single master system multimaster system single master system a typical single master system may be configured, using an icu as the master and four icus as slaves (see figure 13.6). the master device selects the individual slave devices by using four pins of a parallel port to control the four ss pins of the slave devices. the ss pins are pulled high during reset since the master device ports will be forced to be inputs at that time, thus disabling the slave devices. note: in order to prevent a bus conflict on the miso line the master allows only one active slave device during a transmission. for more security, the slave device may respond to the master with the data byte received. then the master will receive the previous byte back from the slave device if all miso and mosi pins are connected and the slave has not written its spi_out register. other transmission security methods can use ports for handshake lines or data bytes with command fields. multi-master system a multi-master system may also be configured by the user. transfer of master control could be implemented using a handshake method through the i/o ports or by an exchange of code messages through the serial peripheral interface system. the multi-master system is principally handled by the mstr bit in the spi_cr register and the modf bit in the spi_status_cr register. clearing sequence after spif = 1 (end of a data byte transfer) 1st step read spi_status_cr read spi_in write spi_in 2nd step spif =0 wcol=0 spif =0 wcol=0 if no transfer has started wcol=1 if a transfer has started clearing sequence before spif = 1 (during a data byte transfer) 1st step 2nd step wcol=0 before the 2nd step read spi_status_cr read spi_in note: writing in spi_out regis- ter instead of reading in spi_in do not reset wcol bit read spi_status_cr or then then then
ST52F500/f503/f504 89/94 figure 13.6 single master configuration 13.4.8 interrupts note: the spi interrupt events are connected to the same interrupt vector (see interrupts chapter). they generate an interrupt if the corresponding enable control bit (spie) and the interrupt mask bit (mskspi) in the int_mask configuration register is set. miso mosi mosi mosi mosi mosi miso miso miso miso ss ss ss ss ss sck sck sck sck sck 5v ports slave mcu slave mcu slave mcu slave mcu master mcu interrupt event event flag enable control bit exit from wait exit from halt spi end of transfer event spif spie yes no master mode fault event modf yes no
ST52F500/f503/f504 90/94 13.5 spi register description in the following sections describe the registers used by the spi. in the 16 pin devices the spi is not present and the described register aren't used 13.5.1 spi configuration registers. spi control register (spi_cr) configuration register 20 (014h) read/write reset value: 0000 0000 (00h) bit 7: spie serial peripheral interrupt enable. this bit is set and cleared by software. 0: interrupt is inhibited 1: an spi interrupt is generated whenever spif=1 or modf=1 in spi_status_cr bit 6: spe serial peripheral output enable. this bit is set and cleared by software. it is also cleared by hardware when, in master mode, ss=0 (see section 13.4.5 master mode fault). 0: i/o port connected to pins 1: spi alternate functions connected to pins note: the spe bit is cleared by reset, so the spi peripheral is not initially connected to the pins. bit 5: spr2 divider enable. this bit is set and cleared by software and it is cleared by reset. it is used with the spr[1:0] bits to set the baud rate. refer to table 13.1. 0: divider by 2 enabled 1: divider by 2 disabled note: this bit has no effect in slave mode. bit 4: mstr master/slave mode select. this bit is set and cleared by software. it is also cleared by hardware when, in master mode, ss=0 (see section 13.4.5 master mode fault). 0: slave mode is selected 1: master mode is selected, the function of the sck pin changes from an input to an output and the functions of the miso and mosi pins are reversed. bit 3: cpol clock polarity. this bit is set and cleared by software. this bit determines the steady state of the serial clock. the cpol bit affects both the master and slave modes. 0: the steady state is a low value at the sck pin. 1: the steady state is a high value at the sck pin. note: spi must be disabled by resetting the spe bit if cpol is changed at the communication byte boundaries. bit 2: cpha clock phase. this bit is set and cleared by software. 0: the first clock transition is the first data capture edge. 1: the second clock transition is the first capture edge. bit 1-0: spr1 - spr0 serial peripheral rate. these bits are set and cleared by software. used with the spr2 bit, they select one of six baud rates to be used as the serial clock when the device is a master (see table 13.1). these 2 bits have no effect in slave mode. remark: it is recommended to write the spi_cr register after the spi_status_cr register. spi control-status register (spi_status_cr) configuration register 21 (015h) read/write reset value: 0000 0000 (00h) 70 spie spe spr2 mstr cpol cpha spr1 spr2 table 13.1 serial peripheral baud rate serial clock spr2 spr1 spr0 f cpu /2 1 0 0 f cpu /4 0 0 0 f cpu /8 0 0 1 f cpu /16 1 1 0 f cpu /32 0 1 0 f cpu /64 0 1 1 70 spif wcol or modf - sod ssm ssi
ST52F500/f503/f504 91/94 bit 7: spif serial peripheral data transfer flag. (read only) this bit is set by hardware when a transfer has been completed. an interrupt is generated if spie=1 in the spi_cr register. it is cleared by a software sequence (an access to the spi_status_cr register followed by a read or write to the spi_in/ spi_out registers). 0: data transfer is in progress or has been approved by a clearing sequence. 1: data transfer between the device and an external device has been completed. note: while the spif bit is set, all writes to the spi_out register are inhibited. bit 6: wcol write collision status (read only). this bit is set by hardware when a write to the spi_out register is done during a transmit sequence. it is cleared by a software sequence (see figure 13.5). 0: no write collision occurred 1: a write collision has been detected bit 5: or spi overrun error (read only). this bit is set by hardware when the byte currently being received in the shift register is ready to be transferred into the spi_in register while spif = 1 (see section 13.4.6 overrun condition). an interrupt is generated if spie = 1 in spi_cr register. it is cleared by a software sequence (read of the spi_status_cr register followed by a read in spi_in or write of the spi_out register). 0: no overrun error. 1: overrun error detected. bit 4: modf mode fault flag (read only). this bit is set by hardware when the ss pin is pulled low in master mode (see section 13.4.5 master mode fault). an spi interrupt can be generated if spie=1 in the spi_cr register. this bit is cleared by a software sequence (an access to the spi_status_cr register while modf=1 followed by a write to the spi_cr register). 0: no master mode fault detected 1: a fault in master mode has been detected bit 3: not used. bit 2: sod spi output disable this bit is set and cleared by software. when set, it disables the alternate function of the spi output (mosi in master mode / miso in slave mode) 0: spi output not disable 1: spi output disable. bit 1: ssm ss mode selection this bit is set and cleared by software. when set, it disables the alternate function of the spi slave select pin and use the ssi bit value instead of. 0: ss pin used by the spi. 1: ss pin not used (i/o mode), ssi bit value is used. bit 0: ssi ss internal mode this bit is set and cleared by software. it replaces pin ss of the spi when bit ssm is set to 1. ssi bit is active low slave select signal when ssm is set to 1. 0 : slave selected 1 : slave not selected. remark: it is recommended to write the spi_status_cr register before the spi_cr register. 13.5.2 spi input register. spi data input register (spi_in) input register 5 (05h) read only reset value: 0000 0000 (00h) bit 7-0: spidi7-spidi0 received data. the spi_in register is used to receive data on the serial bus. note: during the last clock cycle the spif bit is set, a copy of the data byte received in the shift register is moved to a buffer. when the user reads the serial peripheral data i/o register, the buffer is actually being read. 70 spidi7 spidi6 spidi5 spidi4 spidi3 spidi2 spidi1 spidi0
ST52F500/f503/f504 92/94 warning: a read to the spi_in register returns the value located in the buffer and not the contents of the shift register (see figure 13.2). 13.5.3 spi output register. spi data output register (spi_out) output register 5 (05h) read only reset value: 0000 0000 (00h) bit 7-0: spido7-spido0 data to be transmitted. the spi_out register is used to transmit data on the serial bus. in the master device only a write to this register will initiate transmission/reception of another byte. warning: a write to the spi_out register places data directly into the shift register for transmission. 70 spido7 spido6 spido5 spido4 spido3 spido2 spido1 spido0
ST52F500/f503/f504 93/94
94/94 full product information at http://www.st .com/five information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specification mentioned in this publication are subject to change without notice. this publication supersedes and replaces all information previously supplied. stmicroelectronics products are not authorized for use as critical components in life support devices or systems without express writt en approval of stmicroelectronics. the st logo is a registered trademark of stmicroelectronics ? 2002 stmicroelectronics printed in italy all rights reserved stmicroelectronics group of companies australia - brazil - china - canada - finland - france - germany - hong kong - india - israel - italy - japan - malaysia - malta - morocco - singapore - spain - sweden - switzerland - united kingdom - u.s.a. http://www.st.com

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