Post by thread:Followup of execution problems

Hi, Thanks to David Thomas, Stuart Lea, Don lekei and Eric Smith for a some previous advice. I am still having trouble, that I can't see how to attack. My question then, was for help about why might a PIC16C57 program work fine on the Microchip simulator, but never on the chip. I believe that I have properly checked: 1. that the FSR is adjusted for the right data page 2. the status flags are set for the right program page 3. FSR has been initialised properly 4. All other registers that could affect this have been checked for initialisation 5. the RTCC is not compared directly but with the value in W 6. page select bit are properly maintained; To describe the situation. I wanted to extend code from the ap notes for provide me with 4 general purpose timers. these were designed to count down and then trigger a flag (and action) when they timed out. The code is yet to be modified for decimal rather than hex, but that is just work for later. The problem. The timers never time out. analysis: If we set the timer with a value of 5 (seconds), but XORing with constants it has been possible to trigger LEDs to indicate that the value is decremented. BUT, the timer is decremented from 5 to 4, and then next time from 4 to 3, BUT it never seems to be decremented to 2 or to 1. Hopefully you could help by: 1. Suggestions for further analysis 2. Suggestions of what might be wrong. I am becomeing quite frustrated - it affects my confidence in embedded programming. There are not spurious processes that could be messing it up (it is not a DOS program!), so I am failing to see where the difficulty could be. Thanks for any advice. The code is appended. PS the watchdog is not timeing out. The chips have been tried with it on and off. I also have the chip blinking an LED (Port A bit 3) to ensure that it is still ticking over, and that never stops or fails. regards Gary Gaskell DSTC Cooperative Research Centre for Distributed Systems Technology Queensland University of Technology Ph +61-7-864 1051 FAX +61-7-864 1282 Email spam_OUTgaskellTakeThisOuTdstc.qut.edu.au URL http://ftp.dstc.edu.au/intro.html I am including a listing file and a source file. ------------------------------------------------------------------------------ 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 1 Line PC Opcode 0001 ; TST2.asm May 1, 1994 0002 ; modified to test PIC out and do demos. extra comments added 0003 ; Insert BCD timers and test 0004 ; Original code from the Applications notes from Microchi p. 0005 ; 0006 ; Gary Gaskell mods for count down timers. 0007 ; 0008 LIST P= 16C57 0009 ; 0010 ; Coding policy: 0011 ; A routine is a section of code. This defintion may be r efined to two types 0012 ; of routines. The first is a PROCEDURE. Procedures may be called 0013 ; using the stack of the PIC. The second is a "CODE SEQU ENCE". This 0014 ; type of routine may not be called, only jumped/branched to. The 0015 ; intention is to limit the likelihood to too many calls resulting in 0016 ; an overflow on the stack. 0017 ; Level 0 This code is Base code (stack is empty) 0018 ; Level 1 Called from base code, may call another rou tine. (stack=1) 0019 ; Displine and quality code requires that a r eturn is 0020 ; executed. 0021 ; Level 2 Called from base or Level 1 code. The stack is now full 0022 ; so no calls are allowed. branching only, b ut a return 0023 ; is essential to unwind the stack. 0024 ; CONSTANTS will be in UPPERCASE, with variables in lowe rcase. 0025 ; 0026 ; 0027 ; define equates: 0028 ; 0029 07FF PIC57 equ 7FFH 0030 ; 0031 ; external osc used = 4.096mHz. prescaler of 32 used, wh ich gives a 0032 ; 31.25 microsec inc of the RTCC. If the rtcc is initial ly loaded with 96 0033 ; it would overflow to 0 in 5.00ms. giving 0.00% error 0034 ; If the crystal is 4.000 Mhz (prototype Xtal), NB 4Mhz x tal gives 1 Mhz 0035 ; internal clock. then overflow at 32usec, 0036 ; requiring 156.25 rtcc cycles, ie msecs should be 100, b ut an error needs 0037 ; to be corrected. , Easier option is to decrease interva l to 4 ms and to 0038 ; alter the constant for the seconds to 250 (249 actually ). NB gives 0039 ; 4000 instructions before the RTCC overflow must be caug ht. 0040 ; 0041 ; MTICKS EQU d'96' ; for 4.096 Mhz xtal 0042 ; MTICKS EQU d'100' ; for 4.000Mhz xtal 0043 ; MTICKS equ d'131' ; for 4.000MHz xtal and 4msec overflow 0044 0001 MTICKS equ d'1' ; for testing 0045 ; Number of rttc timeouts to equal one second. 0046 ; NumRollover equ d'199' 0047 ; NumRollOver equ d'249' 0048 0001 NumRollover equ d'1' ; for testing 0049 ; 0050 ; needs fixing to right value 0051 0000 key_hit equ 0 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 2 Line PC Opcode 0052 0053 0001 same equ 1 ; register operation sourc e=dest 0054 0000 C EQU 0 0055 0000 BEP EQU 0 0056 0000 RTATS EQU 0 0057 0001 DC EQU 1 0058 0001 HR10 EQU 1 0059 0002 Z EQU 2 0060 0002 HR EQU 2 0061 0004 MIN EQU 4 0062 0004 FLASH EQU 4 0063 0005 PA0 EQU 5 0064 0006 PA1 EQU 6 0065 0000 F0 EQU 0 0066 0005 LEDon EQU 5 ; is set if the LED is on. bit 5 of alflag 0067 0003 led equ 3 ; bit of portA for the le d. 0068 0005 dataP1 equ 5 ; bit 5 of FSR (sets from DP0 to dataPg 1) 0069 ; 0070 ; Constants for timers etc 0071 ; these are set if the timer is active 0072 0000 timer1 equ 0 ; bit numbers for flag "t imeFlag" 0073 0001 timer2 equ 1 0074 0002 timer3 equ 2 0075 0003 timer4 equ 3 0076 0077 ; these are set if the timer has finished and awa its action 0078 0004 tmr1end equ 4 0079 0005 tmr2end equ 5 0080 0006 tmr3end equ 6 0081 0007 tmr4end equ 7 0082 0083 ; This is the number of bytes that separate the t imer, from 0084 ; a copy of its setup values 0085 0008 OFFSET equ 8 0086 0087 0088 ; 0089 ; DEFINE RAM LOCATIONS 0090 ; 0091 0001 RTCC EQU 1 0092 0002 PC EQU 2 0093 0003 STATUS EQU 3 0094 0004 FSR EQU 4 0095 0005 PORT_A EQU 5 0096 0006 PORT_B EQU 6 0097 0007 PORT_C EQU 7 0098 ; 0099 0008 MSTMR EQU 8 ; ms timer 0100 0009 STMR EQU 9 ; sec timer 0101 ; 0102 000A MTMR EQU 0A ; min timer 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 3 Line PC Opcode 0103 000B HTMR EQU 0B ; hour timer 0104 ; 0105 000C temp EQU 0C ; 0106 000D tmp2 EQU 0D ; 0107 ; 0108 000E timeFlag EQU 0E ; min entry 0109 000F dummy EQU 0F ; hour entry 0110 ; 0111 ; New data page : Page 0 0112 0011 tmp3 EQU 11 0113 0012 genFlag equ 12 ; general flags 0114 0013 digit equ 13 0115 0014 new_key equ 14 0116 0015 KEY_NIBL EQU 15 0117 0016 DEBOUNCE EQU 16 0118 0119 0017 MIN_SEC EQU 17 ; MIN/seconds timer 0120 ; 0121 ; PORT pin definitions 0122 ; 0123 ; Port A: s 0124 ; bit0 led to flash 0125 ; bit 1-3 unsed i/o 0126 ; 0127 ; define the RAM locations of DATA PAGE 1 (timers) 0128 ; NB to use these RAM locations (variables) the correct b its of the 0129 ; FSR must be set (5&6). 0130 ; setup 5 timers. Each will store BCD time values and be decremented to- 0131 ; wards zero. NB if these timers are moved the code that works on that 0132 ; must be updated. 0133 ; 0134 ; Timers placed in Data Page 1 0135 0030 stmr1 equ 30 0136 0031 mtmr1 equ 31 0137 0032 stmr2 equ 32 0138 0033 mtmr2 equ 33 0139 0034 stmr3 equ 34 0140 0035 mtmr3 equ 35 0141 0036 stmr4 equ 36 0142 0037 mtmr4 equ 37 0143 0038 stmr1Val equ 38 0144 0039 mtmr1Val equ 39 0145 003A stmr2Val equ 3A 0146 003B mtmr2Val equ 3B 0147 003C stmr3Val equ 3C 0148 003D mtmr3Val equ 3D 0149 003E stmr4Val equ 3E 0150 003F mtmr4Val equ 3F 0151 ; 0152 ; 0153 ; 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 4 Line PC Opcode 0154 ; ******************************************************* ********************* 0155 0000 org 0 0156 START 0157 0000 0A1E goto initialise 0158 ; this routine runs a test on the leds 0159 ; all the relevent leds are lit up for 2 secs. 0160 ; 0161 test_hardware 0162 0001 0C01 movlw D'1' ; flash every two for 2 se cs 0163 0002 0037 movwf min_sec 0164 ; 0165 ; 0166 norm_time 0167 0003 0412 bcf genFlag, 0 ; put in real time 0168 0004 0432 bcf genFlag, 1 0169 ; 0170 time_loop 0171 ; call update_display 0172 ; bsf status, PA1 ; goto page 2 0173 ; call service_keys 0174 0005 05A3 bsf status, PA0 ; goto page 1 0175 0006 0900 call update_timers ; wait and update timers (Realtime) Warning: [Warning 1] : line 175 : Address change across page boundary, ensure page bits are set 0176 0007 04A3 bcf status, PA0 0177 0008 0D00 iorlw 0 ; 0178 0009 0743 btfss status, Z ; 0179 000A 0A0C goto GPtime ; 0180 ; movf genFlag, w ; see if in atm 0181 ; andlw B'00000011' 0182 ; xorlw B'00000001' 0183 ; btfsc status, z ; skip if not 0184 retrn 0185 000B 0A05 goto time_loop 0186 0187 GPtime 0188 ; code sequence to call general purpose timers 0189 ; Pre: only called after a second interval has past 0190 0191 000C 05A3 bsf status, PA0 ; goto page 1 0192 000D 0975 call servTmr ; service the gen purpose timers Warning: [Warning 2] : line 192 : Address change across page boundary, ensure page bits are set 0193 000E 09A5 call TmrAct Warning: [Warning 3] : line 193 : Address change across page boundary, ensure page bits are set 0194 000F 04A3 bcf status, PA0 ; reset page flags 0195 0010 0915 call ChangeState 0196 0011 0A0B goto retrn 0197 0198 on 0199 ; Level 2 routine. 0200 ; set led on, by setting it low, set in flag and at port. 0201 ; Pre: 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 5 Line PC Opcode 0202 ; Post: 0203 0012 05B2 bsf genflag, LEDON 0204 0013 0465 bcf port_a, led 0205 0014 0800 retlw 0 0206 ; 0207 ChangeState 0208 ; Level 2 routine 0209 ; routine to change the state of the led. this is only e ntered if the 0210 ; min_sec timer has reached zero. 0211 ; 0212 ; Pre: 0213 ; POst: 0214 ; 0215 ; reset value for blinks the led ever 2 secs 0216 0015 0C01 movlw D'01' ; 2 secs 0217 0016 0037 movwf min_sec 0218 ; check the led status on/off? 0219 0017 0212 movf genflag, w 0220 0018 0E20 andlw B'00100000' 0221 0019 0643 btfsc status, z ; if ledon is on 0222 001A 0A12 goto on ; turn it on 0223 001B 0565 bsf port_a, led ; turn it off 0224 001C 04B2 bcf genflag, ledon 0225 001D 0800 retlw 0 0226 0227 0228 0229 ;******************************************************** ****************; 0230 ; This routine set up ports A, B, C and the internal 0231 ; real time clock counter. 0232 ; Level 1 routine 0233 ; Pre: 0234 ; Post: Timers have been setup. 0235 ; Ports have been setup 0236 ; The prescaler is set 0237 ; 0238 initialise 0239 001E 0064 clrf FSR 0240 001F 0C0F movlw B'00001111' ; make active high 0241 0020 0025 movwf port_a 0242 0021 0C00 movlw B'00000000' ; set port A as outputs 0243 0022 0005 tris port_a 0244 ; 0245 0023 0CFF movlw B'11111111' ; set levels high 0246 0024 0026 movwf port_b 0247 0025 0C00 movlw B'00000000' ; set portB as output 0248 0026 0006 tris port_b 0249 ; 0250 0027 0C00 movlw B'00000000' ; set levels low 0251 0028 0027 movwf port_c 0252 0029 0C00 movlw B'00000000' ; set port C as output 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 6 Line PC Opcode 0253 002A 0007 tris port_c 0254 ; 0255 ; OPTION REG setup 0256 ; bits 7,6,5,4,3,2,1,0 0257 ; 6,7 not avail 0258 ; 5 rt source o = int, 1, edge on rtcc pin 0259 ; 4 rtcc edge l->H '0', H-->L '1' 0260 ; 3 prescaler assignment 0 rtcc, 1 wdt 0261 ; 1,2,3 ratio of prescaler '100' = 1:32 0262 ; 000 -> scale 1:2 0263 ; 111 -> scale 1:256 0264 ; NB if scale used for wdt, then ratio is 1/2 of the rtcc scale 0265 ; movlw B'00000100' ; set up prescaler (1:32 ) 0266 002B 0C00 movlw B'00000000' ; for testing 0267 002C 0002 option 0268 ; 0269 002D 0C01 movlw MTICKS ; rtcc = 5msecs 0270 ; init the rtcc with a value MTICKS, so that when it time s out it is 0271 ; almost exactly 5msecs. 0272 002E 0021 movwf rtcc 0273 002F 0068 clrf mstmr 0274 0030 0069 clrf stmr 0275 0031 006A clrf mtmr 0276 0032 0C12 movlw 12H ; make hours = 12 0277 0033 002B movwf htmr 0278 0034 0072 clrf genFlag 0279 0035 05A3 bsf status, PA0 0280 0036 0940 call initTmr Warning: [Warning 4] : line 280 : Address change across page boundary, ensure page bits are set

0281 0037 0C30 movlw stmr1 ; set W = timer1 0282 ; call setTimer 0283 ; testing 0284 0038 0C05 movlw 5 0285 0039 05A4 bsf fsr, DataP1 0286 003A 0030 movwf stmr1 0287 003B 04A4 bcf fsr, DataP1 0288 0289 003C 050E bsf timeFlag, timer1 ; activate timer 0290 003D 04A3 bcf status, PA0 0291 003E 0A01 goto test_hardware 0292 ; 0293 ; 0294 ; ******************************************************* ****************** 0295 ; 0296 ; TIMER MODULE 0297 ; 0298 ; ******************************************************* ****************** 0299 ; All routines related to timer update are located at add ress 0300 ; 200 and above. 0301 ; 0302 0000 org 200 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 7 Line PC Opcode 0303 ; 0304 ; This routine is called on every loop. 0305 update_timers 0306 ; 0307 ; Pre: 0308 ; Post: returns 1 in W if a 1 second interval has past 0309 0310 0200 0004 clrwdt 0311 timerLoop 0312 ; the timer loop is currently set to time out every 5ms. NB it must be 0313 ; less than 18 ms or the watchdog may time out. 0314 0201 0000 nop ; allow time for rtcc = 0 to be available 0315 0202 0201 movf rtcc, w ; is rtcc =0 0316 0203 0743 btfss status, z ; if 0 then skip 0317 0204 0A01 goto timerLoop ; else loop 0318 ; setup real time counter again to count out the next 5ms 0319 0205 0C01 movlw MTICKS ; rtcc = 5ms or 4ms 0320 0206 0021 movwf rtcc 0321 0207 02A8 incf mstmr ; inc 5 ms 0322 ; btfsc genFlag, key_hit ; no key hit, then sk ip 0323 ; goto chk_de_bounce ; else debounce 0324 ; 0325 ; check to see if a second has rolled around. IE 200 x 5m s = 1 sec 0326 ; or 250 x 4ms = 1sec 0327 0208 0208 movf mstmr, 0 ; get mstmr in W 0328 0209 0F01 xorlw NumRollOver ; if enough to equal 1 se c then skip 0329 020A 0743 btfss status, z 0330 020B 0800 retlw 0 ; return as not a second interval 0331 ; 0332 ; inc seconds count 0333 020C 0068 clrf MSTMR ; CLEAR ms-TMR 0334 020D 0217 movf min_sec, w ; get min_sec timer 0335 020E 0E0F andlw B'00001111' ; mask minutes 0336 020F 0743 btfss status, z ; zero then skip 0337 0210 00F7 decf min_sec 0338 0211 0C09 movlw stmr ; load fsr with s_tmr 0339 0212 0024 movwf fsr 0340 0213 0926 call inc_60 ; inc secs 0341 0214 0D00 iorlw 0 ; 0342 0215 0743 btfss status, z ; 0343 0216 0801 retlw 1 ; only a sec passed 0344 ; 0345 ; inc minutes count 0346 0217 03B7 swapf min_sec 0347 0218 0217 movf min_sec, w ; get min_sec in w 0348 0219 0E0F andlw B'00001111' ; mask seconds 0349 021A 0743 btfss status, z ; skip is not set 0350 021B 00F7 decf min_sec ; else dec 0351 021C 03B7 swapf min_sec ; swap back 0352 ; call chk_silnc_tim ; silence on? 0353 021D 0C0A movlw mtmr ; inc mins 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 8 Line PC Opcode 0354 021E 0024 movwf fsr ; 0355 021F 0926 call inc_60 0356 0220 0D00 iorlw 0 ; do an operation 0357 0221 0743 btfss status, z ; if 0 then skip 0358 0222 0801 retlw 1 ; 0359 ; 0360 ;inc hour count 0361 ; Level ? 0362 ; Increment the hour count. 0363 0223 0C0B movlw htmr ; get htmr in fsr 0364 0224 0024 movwf fsr 0365 0225 0937 call inc_hr 0366 ; 0367 inc_60 0368 ; inc the register pointed to by the FSR modulo 60. NB B CD is used. 0369 ; Pre: The Fsr is a timer register that is desired to be incremented by 1 0370 ; modulo 60. 0371 ; Post: inc has occurred. If the result is 1 a inc was n ormal. If the 0372 ; result is 0, then the tmr overflowed (=60) 0373 0226 02A0 incf f0 ; inc and get in w 0374 0227 0200 movf f0, 0 0375 0228 0E0F andlw B'00001111' ; mask high bits 0376 0229 0F0A xorlw B'00001010' ; = 10 them make it 0 0377 022A 0743 btfss status, z 0378 ; normal condition, return 1 (okay), unit digit i ncremented 0379 022B 0801 retlw 1 ; else ret non zero 0380 022C 0CF0 movlw B'11110000' ; zero lsb 0381 022D 0160 andwf f0 0382 022E 03A0 swapf f0 ; swap indirect 0383 022F 02A0 incf f0 0384 0230 0200 movf f0,0 ; get in w 0385 0231 03A0 swapf f0 ; swap f0 back 0386 0232 0F06 xorlw D'6' 0387 0233 0743 btfss status,z 0388 ; normal condition, return 1, tens digit incremen ted 0389 0234 0801 retlw 1 0390 ; mod 60 overflow, return 0. 0391 0235 0060 clrf f0 0392 0236 0800 retlw 0 0393 ; 0394 inc_hr 0395 ; FSR is pointing to the timer. 0396 ; i don't think that the hour timer is BCD. 0397 ; pre: 0398 ; post: 0399 0237 02A0 incf f0 ; inc hour timer 0400 0238 0200 movf f0, w 0401 ; 0402 chk_13 0403 0239 0200 movf f0, w ; get in w 0404 023A 0F12 xorlw 12h ; see if 13 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 9 Line PC Opcode 0405 023B 0743 btfss status, z ; yes then skip 0406 023C 0000 nop 0407 023D 0801 retlw 1 ; flags that a second int erval has past 0408 ; 0409 set_1_hr 0410 023E 0C01 movlw B'00000001' ; SET TO 1 0411 023F 0020 MOVWF f0 0412 0413 ; The general purpose timers are not affected if their va lue is zero. 0414 ; 0415 InitTmr 0416 ; Initialise timers 0417 ; Timers can run for 255 minutes or over 4 hours. 0418 ; Procedure to initialise the general purpose timers syst em. This will be 0419 ; by constants in the first place, but later from the NV RAM. 0420 ; Pre: Data page is 0 0421 ; Post: Data page is 0 0422 ; Initialise the backup of the timer values. (this will eventually 0423 ; come from the NVRAM) 0424 ; 0425 ; Set all timers to zero in the first instance. 0426 ; 0427 ; set data page to 1 0428 0240 05A4 bsf FSR, dataP1 0429 0241 006E clrf timeFlag 0430 ; move in address of first timer and then increment the addr, clearing 0431 ; each timer as we step through the timers. Curren tly this is the 0432 ; first 8 bytes of data page 1 0433 0242 0C30 movlw stmr1 0434 ClrLoop 0435 0243 0024 movwf fsr 0436 0244 05A4 bsf FSR, dataP1 ; maintain data page 0437 0245 0060 clrf f0 ; clears seconds part of timer 0438 0246 02A4 incf fsr, same ; inc so to clear minu tes part 0439 0247 0060 clrf f0 ; clears mins part 0440 ; test to see all timers are clear 0441 0248 0204 movf fsr, W 0442 0249 0F37 xorlw mtmr4 0443 024A 0E0F andlw b'00001111' ; ensure high nibble i s clear 0444 024B 0743 btfss STATUS, Z ; = --> skip 0445 024C 0A43 goto ClrLoop 0446 0447 ; install some setup values 0448 024D 0C10 movlw 10 0449 024E 0038 movwf stmr1Val 0450 0451 024F 0C01 movlw 1 0452 0250 003A movwf stmr2Val 0453 0251 003C movwf stmr3Val 0454 0252 003E movwf stmr4Val 0455 0253 003B movwf mtmr2Val 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 10 Line PC Opcode 0456 0254 0C02 movlw 2 0457 0255 003D movwf mtmr3Val 0458 0256 0C10 movlw 10 0459 0257 003F movwf mtmr4Val 0460 ; reset data page to 0 0461 0258 04A4 bcf FSR, DataP1 0462 0259 0800 retlw 0 0463 0464 SetTimer 0465 ; This procedure sets the timer to it's backup value 0466 ; 0467 ; Pre: W is the timer (the address of the seconds part o f the tmr) 0468 ; Data Page is 0 0469 ; Post: The timer is set to the corresponding timer setu p values 0470 ; Data page is 0 0471 0472 ; the offset to the setup values is currently 8 bytes hig her than the 0473 ; timer variable locations 0474 0475 ; set to the timer data page 0476 025A 05A4 bsf FSR, dataP1 0477 0478 ; firstly transfer the seconds values 0479 ; calculate timer using the offset in W 0480 025B 002C movwf temp ; Save timer address 0481 025C 0C08 movlw OFFSET 0482 025D 01CC addwf temp, w ; calculate reg of the i nitial value 0483 025E 0024 movwf FSR ; save this address in F SR 0484 025F 05A4 bsf FSR, dataP1 ; maintain data page 0485 ; get timer (secs) value 0486 0260 0200 movf f0, W ; get setup value 0487 0261 002D movwf tmp2 ; save value, then get b ack timer address 0488 0262 020C movf temp, W ; get timer address agai n 0489 0263 0024 movwf fsr 0490 0264 05A4 bsf FSR, dataP1 ; maintain data page 0491 0265 020D movf tmp2, W 0492 0266 0020 movwf f0 0493 0494 ; Now transfer the minutes value 0495 0267 0C09 movlw OFFSET+1 0496 0268 01CC addwf temp, w ; calculate reg of the i nitial value 0497 0269 0024 movwf FSR ; save this address in F SR 0498 026A 05A4 bsf FSR, dataP1 ; maintain data page 0499 0500 ; get timer (mins) value 0501 026B 0200 movf f0, W 0502 026C 002D movwf tmp2 ; save value, then get b ack timer address 0503 026D 02AC incf temp, same 0504 026E 020C movf temp, W 0505 026F 0024 movwf fsr 0506 0270 05A4 bsf FSR, dataP1 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 11 Line PC Opcode 0507 0271 020D movf tmp2, W 0508 0272 0020 movwf f0 0509 0273 04A4 bcf FSR, dataP1 ; reset data page pointe r 0510 0274 0800 retlw 0 ; ??? 0511 0512 0513 0514 ServTmr 0515 ; Services the timers, decrementing the active timers 0516 ; Pre: Must called from main loop, as there are calls in this routine 0517 ; Data Page is 0 0518 ; Post: Data Page is 0 0519 0520 ; testing 0521 ; bcf port_a, 2 0522 ; set to data page 1 0523 0275 05A4 bsf FSR, dataP1 0524 0525 ; get timer address in working register 0526 0276 0C30 movlw stmr1 0527 0528 ; check to see timer active 0529 0277 060E btfsc timeFlag, timer1 0530 ; if it is decrement it 0531 0278 0990 call timerDec 0532 0533 ; if the value returned in w is 1, then the timer i s finished 0534 ; so set it's flag 0535 0279 0F01 xorlw d'1' 0536 027A 0643 btfsc status, z ; 0537 027B 058E bsf timeFlag, tmr1end ; 0538 0539 027C 0C32 movlw stmr2 0540 027D 062E btfsc timeFlag, timer2 0541 027E 0990 call timerDec 0542 ; if the value returned in w is 1, then the timer i s finished 0543 ; so set it's flag 0544 027F 0F01 xorlw d'1' 0545 0280 0643 btfsc status, z ; 0546 0281 05AE bsf timeFlag, tmr2end ; 0547 0548 0282 0C34 movlw stmr3 0549 0283 064E btfsc timeFlag, timer3 0550 0284 0990 call timerDec 0551 ; if the value returned in w is 1, then the timer i s finished 0552 ; so set it's flag 0553 0285 0F01 xorlw d'1' 0554 0286 0643 btfsc status, z ; 0555 0287 05CE bsf timeFlag, tmr3end ; 0556 0557 0288 0C36 movlw stmr4 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 12 Line PC Opcode 0558 0289 066E btfsc timeFlag, timer4 0559 028A 0990 call timerDec 0560 ; if the value returned in w is 1, then the timer i s finished 0561 ; so set it's flag 0562 028B 0F01 xorlw d'1' 0563 028C 0643 btfsc status, z ; 0564 028D 05EE bsf timeFlag, tmr4end ; 0565 0566 028E 04A4 bcf FSR, dataP1 0567 028F 0800 retlw 0 0568 0569 0570 timerDec 0571 ; Pre: W = stmr1 | stmr2 | stmr3 | stmr4 (addresses) 0572 ; the seconds are never 0, either counting down, or 0573 ; reset to 60 0574 ; post: 0575 ; 0576 ; testing 0577 ; bcf port_a, 2 0578 0579 0290 0024 movwf fsr 0580 0291 05A4 bsf FSR, dataP1 ; ensure that data pag e remains ok 0581 0292 00E0 decf f0, same ; dec seconds, then 0582 0583 ; ******************************************************* ***************** 0584 ; ******************************************************* ***************** 0585 ; This is where I have found the timer not to progress. It will light the 0586 ; LED on port A if the Xorlw is for 3 or 4 as it counts d own, but it never 0587 ; gets to the stage where comparsion (via XOR) with 1 or 2, lights the LED. 0588 ; I take this to mean that, it never gets to the value of 1 or 2. 0589 0590 ; movf f0, w 0591 ; xorlw 4 0592 ; btfsc status, z 0593 ; bcf Port_A, 1 0594 ; xorlw 3 0595 ; btfsc status, z 0596 ; bcf Port_A, 0 0597 ; xorlw 2 0598 ; btfsc status, z 0599 ; bcf Port_A, 2

0600 0601 0293 0743 btfss status, z ; if zero dec minutes 0602 0294 0800 retlw 0 0603 0604 ZeroSecs 0605 ; The seconds have zeroed, so if no mins left end, else d ec mins 0606 ; and set seconds to 60 0607 ; Pre: FSR is the ADDR of the seconds part of the timer 0608 ; Data page is 1 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 13 Line PC Opcode 0609 ; Post: Data page is 1 0610 ; retlw 1 if the timer is finished 0611 0612 ; testing 0613 0295 0405 bcf Port_a, 0 0614 0296 02A4 incf FSR, same ; so to move to mins part 0615 0297 0200 movf f0, w 0616 0298 0EFF andlw B'11111111' ; test for zero 0617 0299 0743 btfss status, z ; skip if 0 0618 029A 0A9E goto decNow ; else dec the minut es now 0619 0620 ; testing 0621 029B 0445 bcf Port_A, 2 0622 029C 04A4 bcf FSR, dataP1 0623 029D 0801 retlw 1 ; return from timerD ec, noting 0624 ; that the tmr is fi nished 0625 0626 decNow 0627 ; Pre: accessed by a goto from ZeroSecs 0628 ; Post: 0629 029E 00E0 decf f0, same ; dec minutes 0630 029F 00E4 decf FSR, same ; access seconds add ress 0631 02A0 0C60 movlw 60 0632 02A1 0020 movwf f0 ; set seconds 0633 0634 ;testing 0635 02A2 0425 bcf Port_a, 1 0636 02A3 04A4 bcf FSR, dataP1 ; 0637 02A4 0800 retlw 0 ; return from timerD ec 0638 0639 0640 0641 TmrAct 0642 ; Take initial action if a timer is finished. 0643 ; Pre: The finshed flag for the timer is set 0644 ; Post: The finshed flag is cleared 0645 ; testing 0646 ; bcf port_a, 2 0647 0648 02A5 068E init1 btfsc timeFlag, tmr1end 0649 02A6 0AAE goto TmrAct1 0650 02A7 06AE init2 btfsc timeFlag, tmr2end 0651 02A8 0AB5 goto TmrAct2 0652 02A9 06CE init3 btfsc timeFlag, tmr3end 0653 02AA 0ABD goto TmrAct3 0654 02AB 06EE init4 btfsc timeFlag, tmr4end 0655 02AC 0AC5 goto TmrAct4 0656 02AD 0800 retlw 0 ; return from T mrAct routine 0657 ; 0658 02AE 048E TmrAct1 bcf timeFlag, tmr1end ; clear the end ed flag 0659 02AF 040E bcf timeFlag, timer1 ; stop timer de crementing 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 14 Line PC Opcode 0660 ; testing 0661 ; bcf Port_A, 2 0662 02B0 0C32 movlw stmr2 0663 02B1 095A call setTimer 0664 02B2 052E bsf timeFlag, timer2 ; activate time r2 0665 02B3 0405 bcf port_A, 0 0666 02B4 0AA7 goto init2 0667 02B5 04AE TmrAct2 bcf timeFlag, tmr2end ; clear the end ed flag 0668 02B6 042E bcf timeFlag, timer2 ; stop timer de crementing 0669 02B7 0C34 movlw stmr3 0670 02B8 095A call setTimer 0671 02B9 054E bsf timeFlag, timer3 ; activate time r3 0672 02BA 0505 bsf Port_A, 0 ; turn off prev ious led 0673 02BB 0425 bcf Port_A, 1 ; turn on led 0674 02BC 0AA9 goto init3 0675 02BD 04CE TmrAct3 bcf timeFlag, tmr3end ; clear the end ed flag 0676 02BE 044E bcf timeFlag, timer3 ; stop timer de crementing 0677 02BF 0C36 movlw stmr4 0678 02C0 095A call setTimer 0679 02C1 056E bsf timeFlag, timer4 ; activate time r4 0680 02C2 0525 bsf Port_A, 1 ; turn off prev ious led 0681 02C3 0445 bcf Port_A, 2 ; turn on led 0682 02C4 0AAB goto init4 0683 02C5 04EE TmrAct4 bcf timeFlag, tmr4end ; clear the end ed flag 0684 02C6 046E bcf timeFlag, timer4 ; stop timer de crementing 0685 02C7 0545 bsf Port_A, 2 ; turn off prev ious led 0686 02C8 0465 bcf Port_A, 3 0687 02C9 05A3 bsf status, PA0 0688 02CA 05C3 bsf status, PA1 0689 02CB 0BFF goto sys_reset Warning: [Warning 5] : line 689 : Address change across page boundary, ensure page bits are set 0690 02CC 0800 retlw 0 ; return from T mrAct routine 0691 0692 ; 0693 ; 0694 ; ******************************************************* ******************* 0695 0000 org PIC57 0696 sys_reset 0697 07FF 0A00 goto start Warning: [Warning 6] : line 697 : Address change across page boundary, ensure page bits are set 0698 ; 0699 0000 end 16c5x/xx Cross-Assembler V4.14 Released Sun Jul 31 15:05:04 1994 Page 15 Cross-Reference Listing LABEL VALUE DEFN REFERENCES BEP 0 55 55 C 0 54 54 ChangeState 21 207 195 207 ClrLoop 579 434 434 445 DC 1 57 57 DEBOUNCE 22 117 117 F0 0 65 65 373 374 381 382 383 384 385 391 399 400 403 411 437 439 486 492 501 508 581 615 629 632 FLASH 4 62 62 FSR 4 94 94 239 285 287 339 354 364 428 435 436 438 441 461 476 483 484 489 490 497 498 505 506 509 523 566 579 580 614 622 630 636 GPtime 12 187 179 187 HR 2 60 60 HR10 1 58 58 HTMR 11 103 103 277 363 InitTmr 576 415 280 415 KEY_NIBL 21 116 116 LEDon 5 66 66 203 224 MIN 4 61 61 MIN_SEC 23 119 119 163 217 334 337 346 347 350 351 MSTMR 8 99 99 273 321 327 333 MTICKS 1 44 44 269 319 MTMR 10 102 102 275 353 NumRollover 1 48 48 328 OFFSET 8 85 85 481 495 PA0 5 63 63 174 176 191 194 279 290 687 PA1 6 64 64 688 PC 2 92 92 PIC57 2047 29 29 695 PORT_A 5 95 95 204 223 241 243 613 621 635 665 672 673 680 681 685 686 PORT_B 6 96 96 246 248 PORT_C 7 97 97 251 253 RTATS 0 56 56 RTCC 1 91 91 272 315 320 START 0 156 156 697 STATUS 3 93 93 174 176 178 191 194 221 279 290 316 329 336 342 349 357 377 387 405 444 536 545 554 563 601 617 687 688 STMR 9 100 100 274 338 ServTmr 629 514 192 514 SetTimer 602 464 464 663 670 678 TmrAct 677 641 193 641 TmrAct1 686 658 649 658 TmrAct2 693 667 651 667 TmrAct3 701 675 653 675 TmrAct4 709 683 655 683 Z 2 59 59 178 221 316 329 336 342 349 357 377 387 405 444 536 545 554 563 601 617 ZeroSecs 661 604 604 chk_13 569 402 402 dataP1 5 68 68 285 287 428 436 461 476 484 490 498 506 509 523 566 580 622 636 decNow 670 626 618 626 digit 19 114 114 dummy 15 109 109 genFlag 18 113 113 167 168 203 219 224 278 inc_60 550 367 340 355 367 inc_hr 567 394 365 394 init1 677 648 648 init2 679 650 650 666 init3 681 652 652 674 init4 683 654 654 682 initialise 30 238 157 238 key_hit 0 51 51 led 3 67 67 204 223 mtmr1 49 136 136 mtmr1Val 57 144 144 mtmr2 51 138 138 mtmr2Val 59 146 146 455 mtmr3 53 140 140 mtmr3Val 61 148 148 457 mtmr4 55 142 142 442 mtmr4Val 63 150 150 459 new_key 20 115 115 norm_time 3 166 166 on 18 198 198 222 retrn 11 184 184 196 same 1 53 53 438 503 581 614 629 630 set_1_hr 574 409 409 stmr1 48 135 135 281 286 433 526 stmr1Val 56 143 143 449 stmr2 50 137 137 539 662 stmr2Val 58 145 145 452 stmr3 52 139 139 548 669 stmr3Val 60 147 147 453 stmr4 54 141 141 557 677 stmr4Val 62 149 149 454 sys_reset 2047 696 689 696 temp 12 105 105 480 482 488 496 503 504 test_hardwar 1 161 161 291 timeFlag 14 108 108 289 429 529 537 540 546 549 555 558 564 648 650 652 654 658 659 664 667 668 671 675 676 679 683 684 time_loop 5 170 170 185 timer1 0 72 72 289 529 659 timer2 1 73 73 540 664 668 timer3 2 74 74 549 671 676 timer4 3 75 75 558 679 684 timerDec 656 570 531 541 550 559 570 timerLoop 513 311 311 317 tmp2 13 106 106 487 491 502 507 tmp3 17 112 112 tmr1end 4 78 78 537 648 658 tmr2end 5 79 79 546 650 667 tmr3end 6 80 80 555 652 675 tmr4end 7 81 81 564 654 683 update_timer 512 305 175 305 ------------------------------------------------------------------------ and the asm file ; TST2.asm May 1, 1994 ; modified to test PIC out and do demos. extra comments added ; Insert BCD timers and test ; Original code from the Applications notes from Microchip. ; ; Gary Gaskell mods for count down timers. ; LIST P= 16C57 ; ; Coding policy: ; A routine is a section of code. This defintion may be refined to two types ; of routines. The first is a PROCEDURE. Procedures may be called ; using the stack of the PIC. The second is a "CODE SEQUENCE". This ; type of routine may not be called, only jumped/branched to. The ; intention is to limit the likelihood to too many calls resulting in ; an overflow on the stack. ; Level 0 This code is Base code (stack is empty) ; Level 1 Called from base code, may call another routine. (stack=1) ; Displine and quality code requires that a return is ; executed. ; Level 2 Called from base or Level 1 code. The stack is now full ; so no calls are allowed. branching only, but a return ; is essential to unwind the stack. ; CONSTANTS will be in UPPERCASE, with variables in lowercase. ; ; ; define equates: ; PIC57 equ 7FFH ; ; external osc used = 4.096mHz. prescaler of 32 used, which gives a ; 31.25 microsec inc of the RTCC. If the rtcc is initially loaded with 96 ; it would overflow to 0 in 5.00ms. giving 0.00% error ; If the crystal is 4.000 Mhz (prototype Xtal), NB 4Mhz xtal gives 1 Mhz ; internal clock. then overflow at 32usec, ; requiring 156.25 rtcc cycles, ie msecs should be 100, but an error needs ; to be corrected. , Easier option is to decrease interval to 4 ms and to ; alter the constant for the seconds to 250 (249 actually). NB gives ; 4000 instructions before the RTCC overflow must be caught. ; ; MTICKS EQU d'96' ; for 4.096 Mhz xtal ; MTICKS EQU d'100' ; for 4.000Mhz xtal ; MTICKS equ d'131' ; for 4.000MHz xtal and 4msec overflow MTICKS equ d'1' ; for testing ; Number of rttc timeouts to equal one second. ; NumRollover equ d'199' ; NumRollOver equ d'249' NumRollover equ d'1' ; for testing ; ; needs fixing to right value key_hit equ 0 same equ 1 ; register operation source=dest C EQU 0 BEP EQU 0 RTATS EQU 0 DC EQU 1 HR10 EQU 1 Z EQU 2 HR EQU 2 MIN EQU 4 FLASH EQU 4 PA0 EQU 5 PA1 EQU 6 F0 EQU 0 LEDon EQU 5 ; is set if the LED is on. bit 5 of alflag led equ 3 ; bit of portA for the led. dataP1 equ 5 ; bit 5 of FSR (sets from DP0 to dataPg 1) ; ; Constants for timers etc ; these are set if the timer is active timer1 equ 0 ; bit numbers for flag "timeFlag" timer2 equ 1 timer3 equ 2 timer4 equ 3 ; these are set if the timer has finished and awaits action tmr1end equ 4 tmr2end equ 5 tmr3end equ 6 tmr4end equ 7 ; This is the number of bytes that separate the timer, from ; a copy of its setup values OFFSET equ 8 ; ; DEFINE RAM LOCATIONS ; RTCC EQU 1 PC EQU 2 STATUS EQU 3 FSR EQU 4 PORT_A EQU 5 PORT_B EQU 6 PORT_C EQU 7 ; MSTMR EQU 8 ; ms timer STMR EQU 9 ; sec timer ; MTMR EQU 0A ; min timer HTMR EQU 0B ; hour timer ; temp EQU 0C ; tmp2 EQU 0D ; ; timeFlag EQU 0E ; min entry dummy EQU 0F ; hour entry ; ; New data page : Page 0 tmp3 EQU 11 genFlag equ 12 ; general flags digit equ 13 new_key equ 14 KEY_NIBL EQU 15

DEBOUNCE EQU 16 MIN_SEC EQU 17 ; MIN/seconds timer ; ; PORT pin definitions ; ; Port A: s ; bit0 led to flash ; bit 1-3 unsed i/o ; ; define the RAM locations of DATA PAGE 1 (timers) ; NB to use these RAM locations (variables) the correct bits of the ; FSR must be set (5&6). ; setup 5 timers. Each will store BCD time values and be decremented to- ; wards zero. NB if these timers are moved the code that works on that ; must be updated. ; ; Timers placed in Data Page 1 stmr1 equ 30 mtmr1 equ 31 stmr2 equ 32 mtmr2 equ 33 stmr3 equ 34 mtmr3 equ 35 stmr4 equ 36 mtmr4 equ 37 stmr1Val equ 38 mtmr1Val equ 39 stmr2Val equ 3A mtmr2Val equ 3B stmr3Val equ 3C mtmr3Val equ 3D stmr4Val equ 3E mtmr4Val equ 3F ; ; ; ; **************************************************************************** org 0 START goto initialise ; this routine runs a test on the leds ; all the relevent leds are lit up for 2 secs. ; test_hardware movlw D'1' ; flash every two for 2 secs movwf min_sec ; ; norm_time bcf genFlag, 0 ; put in real time bcf genFlag, 1 ; time_loop ; call update_display ; bsf status, PA1 ; goto page 2 ; call service_keys bsf status, PA0 ; goto page 1 call update_timers ; wait and update timers (Realtime) bcf status, PA0 iorlw 0 ; btfss status, Z ; goto GPtime ; ; movf genFlag, w ; see if in atm ; andlw B'00000011' ; xorlw B'00000001' ; btfsc status, z ; skip if not retrn goto time_loop GPtime ; code sequence to call general purpose timers ; Pre: only called after a second interval has past bsf status, PA0 ; goto page 1 call servTmr ; service the gen purpose timers call TmrAct bcf status, PA0 ; reset page flags call ChangeState goto retrn on ; Level 2 routine. ; set led on, by setting it low, set in flag and at port. ; Pre: ; Post: bsf genflag, LEDON bcf port_a, led retlw 0 ; ChangeState ; Level 2 routine ; routine to change the state of the led. this is only entered if the ; min_sec timer has reached zero. ; ; Pre: ; POst: ; ; reset value for blinks the led ever 2 secs movlw D'01' ; 2 secs movwf min_sec ; check the led status on/off? movf genflag, w andlw B'00100000' btfsc status, z ; if ledon is on goto on ; turn it on bsf port_a, led ; turn it off bcf genflag, ledon retlw 0 ;************************************************************************; ; This routine set up ports A, B, C and the internal ; real time clock counter. ; Level 1 routine ; Pre: ; Post: Timers have been setup. ; Ports have been setup ; The prescaler is set ; initialise clrf FSR movlw B'00001111' ; make active high movwf port_a movlw B'00000000' ; set port A as outputs tris port_a ; movlw B'11111111' ; set levels high movwf port_b movlw B'00000000' ; set portB as output tris port_b ; movlw B'00000000' ; set levels low movwf port_c movlw B'00000000' ; set port C as output tris port_c ; ; OPTION REG setup ; bits 7,6,5,4,3,2,1,0 ; 6,7 not avail ; 5 rt source o = int, 1, edge on rtcc pin ; 4 rtcc edge l->H '0', H-->L '1' ; 3 prescaler assignment 0 rtcc, 1 wdt ; 1,2,3 ratio of prescaler '100' = 1:32 ; 000 -> scale 1:2 ; 111 -> scale 1:256 ; NB if scale used for wdt, then ratio is 1/2 of the rtcc scale ; movlw B'00000100' ; set up prescaler (1:32) movlw B'00000000' ; for testing option ; movlw MTICKS ; rtcc = 5msecs ; init the rtcc with a value MTICKS, so that when it times out it is ; almost exactly 5msecs. movwf rtcc clrf mstmr clrf stmr clrf mtmr movlw 12H ; make hours = 12 movwf htmr clrf genFlag bsf status, PA0 call initTmr movlw stmr1 ; set W = timer1 ; call setTimer ; testing movlw 5 bsf fsr, DataP1 movwf stmr1 bcf fsr, DataP1 bsf timeFlag, timer1 ; activate timer bcf status, PA0 goto test_hardware ; ; ; ************************************************************************* ; ; TIMER MODULE ; ; ************************************************************************* ; All routines related to timer update are located at address ; 200 and above. ; org 200 ; ; This routine is called on every loop. update_timers ; ; Pre: ; Post: returns 1 in W if a 1 second interval has past clrwdt timerLoop ; the timer loop is currently set to time out every 5ms. NB it must be ; less than 18 ms or the watchdog may time out. nop ; allow time for rtcc = 0 to be available movf rtcc, w ; is rtcc =0 btfss status, z ; if 0 then skip goto timerLoop ; else loop ; setup real time counter again to count out the next 5ms movlw MTICKS ; rtcc = 5ms or 4ms movwf rtcc incf mstmr ; inc 5 ms ; btfsc genFlag, key_hit ; no key hit, then skip ; goto chk_de_bounce ; else debounce ; ; check to see if a second has rolled around. IE 200 x 5ms = 1 sec ; or 250 x 4ms = 1sec movf mstmr, 0 ; get mstmr in W xorlw NumRollOver ; if enough to equal 1 sec then skip btfss status, z retlw 0 ; return as not a second interval ; ; inc seconds count clrf MSTMR ; CLEAR ms-TMR movf min_sec, w ; get min_sec timer andlw B'00001111' ; mask minutes btfss status, z ; zero then skip decf min_sec movlw stmr ; load fsr with s_tmr movwf fsr call inc_60 ; inc secs iorlw 0 ; btfss status, z ; retlw 1 ; only a sec passed ; ; inc minutes count swapf min_sec movf min_sec, w ; get min_sec in w andlw B'00001111' ; mask seconds btfss status, z ; skip is not set decf min_sec ; else dec swapf min_sec ; swap back ; call chk_silnc_tim ; silence on? movlw mtmr ; inc mins movwf fsr ; call inc_60 iorlw 0 ; do an operation btfss status, z ; if 0 then skip retlw 1 ; ; ;inc hour count ; Level ? ; Increment the hour count. movlw htmr ; get htmr in fsr movwf fsr call inc_hr ; inc_60 ; inc the register pointed to by the FSR modulo 60. NB BCD is used. ; Pre: The Fsr is a timer register that is desired to be incremented by 1 ; modulo 60. ; Post: inc has occurred. If the result is 1 a inc was normal. If the ; result is 0, then the tmr overflowed (=60) incf f0 ; inc and get in w movf f0, 0 andlw B'00001111' ; mask high bits xorlw B'00001010' ; = 10 them make it 0 btfss status, z ; normal condition, return 1 (okay), unit digit incremented retlw 1 ; else ret non zero movlw B'11110000' ; zero lsb andwf f0 swapf f0 ; swap indirect incf f0 movf f0,0 ; get in w swapf f0 ; swap f0 back xorlw D'6' btfss status,z ; normal condition, return 1, tens digit incremented retlw 1 ; mod 60 overflow, return 0. clrf f0 retlw 0 ; inc_hr ; FSR is pointing to the timer. ; i don't think that the hour timer is BCD. ; pre: ; post: incf f0 ; inc hour timer movf f0, w ; chk_13 movf f0, w ; get in w xorlw 12h ; see if 13 btfss status, z ; yes then skip nop retlw 1 ; flags that a second interval has past ; set_1_hr movlw B'00000001' ; SET TO 1 MOVWF f0 ; The general purpose timers are not affected if their value is zero. ; InitTmr ; Initialise timers ; Timers can run for 255 minutes or over 4 hours. ; Procedure to initialise the general purpose timers system. This will be ; by constants in the first place, but later from the NV RAM. ; Pre: Data page is 0 ; Post: Data page is 0 ; Initialise the backup of the timer values. (this will eventually ; come from the NVRAM) ; ; Set all timers to zero in the first instance. ; ; set data page to 1 bsf FSR, dataP1 clrf timeFlag ; move in address of first timer and then increment the addr, clearing ; each timer as we step through the timers. Currently this is the ; first 8 bytes of data page 1 movlw stmr1 ClrLoop movwf fsr bsf FSR, dataP1 ; maintain data page clrf f0 ; clears seconds part of timer incf fsr, same ; inc so to clear minutes part clrf f0 ; clears mins part ; test to see all timers are clear movf fsr, W xorlw mtmr4 andlw b'00001111' ; ensure high nibble is clear btfss STATUS, Z ; = --> skip goto ClrLoop ; install some setup values movlw 10 movwf stmr1Val movlw 1 movwf stmr2Val movwf stmr3Val movwf stmr4Val movwf mtmr2Val movlw 2 movwf mtmr3Val movlw 10 movwf mtmr4Val ; reset data page to 0 bcf FSR, DataP1 retlw 0 SetTimer ; This procedure sets the timer to it's backup value ; ; Pre: W is the timer (the address of the seconds part of the tmr) ; Data Page is 0 ; Post: The timer is set to the corresponding timer setup values ; Data page is 0 ; the offset to the setup values is currently 8 bytes higher than the ; timer variable locations ; set to the timer data page bsf FSR, dataP1 ; firstly transfer the seconds values ; calculate timer using the offset in W movwf temp ; Save timer address movlw OFFSET addwf temp, w ; calculate reg of the initial value movwf FSR ; save this address in FSR bsf FSR, dataP1 ; maintain data page ; get timer (secs) value movf f0, W ; get setup value movwf tmp2 ; save value, then get back timer address movf temp, W ; get timer address again movwf fsr bsf FSR, dataP1 ; maintain data page movf tmp2, W movwf f0 ; Now transfer the minutes value movlw OFFSET+1 addwf temp, w ; calculate reg of the initial value movwf FSR ; save this address in FSR bsf FSR, dataP1 ; maintain data page ; get timer (mins) value movf f0, W movwf tmp2 ; save value, then get back timer address incf temp, same movf temp, W movwf fsr bsf FSR, dataP1 movf tmp2, W movwf f0 bcf FSR, dataP1 ; reset data page pointer retlw 0 ; ??? ServTmr ; Services the timers, decrementing the active timers ; Pre: Must called from main loop, as there are calls in this routine ; Data Page is 0 ; Post: Data Page is 0 ; testing ; bcf port_a, 2 ; set to data page 1 bsf FSR, dataP1 ; get timer address in working register movlw stmr1 ; check to see timer active btfsc timeFlag, timer1 ; if it is decrement it call timerDec ; if the value returned in w is 1, then the timer is finished ; so set it's flag xorlw d'1' btfsc status, z ; bsf timeFlag, tmr1end ; movlw stmr2 btfsc timeFlag, timer2 call timerDec ; if the value returned in w is 1, then the timer is finished ; so set it's flag xorlw d'1' btfsc status, z ; bsf timeFlag, tmr2end ; movlw stmr3 btfsc timeFlag, timer3 call timerDec ; if the value returned in w is 1, then the timer is finished ; so set it's flag xorlw d'1' btfsc status, z ; bsf timeFlag, tmr3end ; movlw stmr4 btfsc timeFlag, timer4 call timerDec ; if the value returned in w is 1, then the timer is finished ; so set it's flag xorlw d'1' btfsc status, z ; bsf timeFlag, tmr4end ; bcf FSR, dataP1 retlw 0 timerDec ; Pre: W = stmr1 | stmr2 | stmr3 | stmr4 (addresses) ; the seconds are never 0, either counting down, or ; reset to 60 ; post: ; ; testing ; bcf port_a, 2 movwf fsr bsf FSR, dataP1 ; ensure that data page remains ok decf f0, same ; dec seconds, then ; ************************************************************************ ; ************************************************************************ ; This is where I have found the timer not to progress. It will light the ; LED on port A if the Xorlw is for 3 or 4 as it counts down, but it never ; gets to the stage where comparsion (via XOR) with 1 or 2, lights the LED. ; I take this to mean that, it never gets to the value of 1 or 2. ; movf f0, w ; xorlw 4 ; btfsc status, z ; bcf Port_A, 1 ; xorlw 3 ; btfsc status, z ; bcf Port_A, 0 ; xorlw 2 ; btfsc status, z ; bcf Port_A, 2 btfss status, z ; if zero dec minutes retlw 0 ZeroSecs ; The seconds have zeroed, so if no mins left end, else dec mins ; and set seconds to 60 ; Pre: FSR is the ADDR of the seconds part of the timer ; Data page is 1 ; Post: Data page is 1 ; retlw 1 if the timer is finished ; testing bcf Port_a, 0 incf FSR, same ; so to move to mins part movf f0, w andlw B'11111111' ; test for zero btfss status, z ; skip if 0 goto decNow ; else dec the minutes now ; testing bcf Port_A, 2 bcf FSR, dataP1 retlw 1 ; return from timerDec, noting ; that the tmr is finished decNow ; Pre: accessed by a goto from ZeroSecs ; Post: decf f0, same ; dec minutes decf FSR, same ; access seconds address movlw 60 movwf f0 ; set seconds ;testing bcf Port_a, 1 bcf FSR, dataP1 ; retlw 0 ; return from timerDec TmrAct ; Take initial action if a timer is finished. ; Pre: The finshed flag for the timer is set ; Post: The finshed flag is cleared ; testing ; bcf port_a, 2 init1 btfsc timeFlag, tmr1end goto TmrAct1 init2 btfsc timeFlag, tmr2end goto TmrAct2 init3 btfsc timeFlag, tmr3end goto TmrAct3 init4 btfsc timeFlag, tmr4end goto TmrAct4 retlw 0 ; return from TmrAct routine ; TmrAct1 bcf timeFlag, tmr1end ; clear the ended flag bcf timeFlag, timer1 ; stop timer decrementing ; testing ; bcf Port_A, 2 movlw stmr2 call setTimer bsf timeFlag, timer2 ; activate timer2 bcf port_A, 0 goto init2 TmrAct2 bcf timeFlag, tmr2end ; clear the ended flag bcf timeFlag, timer2 ; stop timer decrementing movlw stmr3 call setTimer bsf timeFlag, timer3 ; activate timer3 bsf Port_A, 0 ; turn off previous led bcf Port_A, 1 ; turn on led goto init3 TmrAct3 bcf timeFlag, tmr3end ; clear the ended flag bcf timeFlag, timer3 ; stop timer decrementing movlw stmr4 call setTimer bsf timeFlag, timer4 ; activate timer4 bsf Port_A, 1 ; turn off previous led bcf Port_A, 2 ; turn on led goto init4 TmrAct4 bcf timeFlag, tmr4end ; clear the ended flag bcf timeFlag, timer4 ; stop timer decrementing bsf Port_A, 2 ; turn off previous led bcf Port_A, 3 bsf status, PA0 bsf status, PA1 goto sys_reset retlw 0 ; return from TmrAct routine ; ; ; ************************************************************************** org PIC57 sys_reset goto start ; end