2.txt

基于pic的DS1302串行实时时钟程序

   rlf     buff_4, same
   rlf     temp_e, same
   rlf     temp_d, same
   rlf     temp_c, same
   rlf     temp_b, same
   rlf     temp_a, same
   decfsz  count5, same
   goto    adj_dec
   goto    done
adj_dec:
   movlw   temp_e
   movwf   fsr
   call    adj_bcd
   movlw   temp_d
   movwf   fsr
   call    adj_bcd
   movlw   temp_c
   movwf   fsr
   call    adj_bcd
   movlw   temp_b
   movwf   fsr
   call    adj_bcd
   movlw   temp_a
   movwf   fsr
   call    adj_bcd
   goto    bin2bcd_loop
adj_bcd:
   movlw   h'3'
   addwf   indf, w
   movwf   temp_f
   btfsc   temp_f, 3
   movwf   indf
   movlw   h'30'
   addwf   indf, w
   movwf   temp_f
   btfsc   temp_f, 7
   movwf   indf
   return
done:
   return

incw_bcd        ;increment a packed bcd 8bit freg., enter with data in w
                ;ex T Scott Dattalo, 20/4/98
                movwf   scratch
                movlw   11111110b
                addlw   0x9A+1
                subwf   scratch,w
                rlf     scratch,same
                btfss   status,dc
                addlw   -0x06
                btfss   scratch,0
                addlw   -0x60
                rrf     scratch,same    ;result in w
        return          

decw_bcd        ;decrement a packed bcd freg., enter sub with data in w
                ;ex T Scott Dattalo, 20/4/98
                movwf   scratch
                movlw   1
                subwf   scratch,w
                rlf     scratch,same
                btfss   status,dc
                addlw   -0x06   
                btfss   scratch,0
                addlw   -0x60
                rrf     scratch,same    ;result in w
        return

inc_minute_bcd  ;incr minutes reg by 1, check for not overflow 60s
                movf    minute,w
                sublw   0x60            ;59hex means 59dec in packed bcd
                btfsc   status,z
                return                  ;z got set if minutes=59,so don't incr
                movf    minute,w
                call    incw_bcd
                movwf   minute
        return
dec_minute_bcd  ;decrement minute reg, check for zero underflow
                movf    minute,w
                btfsc   status,z
                return                  ;underflow danger, don't decr
                call    decw_bcd
                movwf   minute
        return

inc_hour_bcd    ;incr hours, packed bcd representation
                movf    hour,w
                sublw   0x24
                btfsc   status,z
                return
                movf    hour,w
                call    incw_bcd
                movwf   hour
        return
dec_hour_bcd    ;decrement hour reg, check for zero underflow
                movf    hour,w
                btfsc   status,z
                return                  ;underflow danger, don't decr
                call    decw_bcd
                movwf   hour
        return

inc_date_bcd    ;incr date of month,packed bcd,cheat & assume all months <= 28days
                movf    date,w
                sublw   0x28
                btfsc   status,z
                return
                movf    date,w
                call    incw_bcd
                movwf   date
        return
dec_date_bcd    ;decrement date reg, check for zero underflow
                movf    date,w
                btfsc   status,z
                return                  ;underflow danger, don't decr
                call    decw_bcd
                movwf   date
        return

inc_month_bcd   ;incr month,packed bcd
                movf    month,w
                sublw   0x12
                btfsc   status,z
                return
                movf    month,w
                call    incw_bcd
                movwf   month
        return
dec_month_bcd   ;decrement date reg, check for zero underflow
                movf    month,w
                btfsc   status,z
                return                  ;underflow danger, don't decr
                call    decw_bcd
                movwf   month
        return

inc_year_bcd    ;incr year, packed bcd
                movf    year,w
                sublw   0x99
                btfsc   status,z
                return
                movf    year,w
                call    incw_bcd
                movwf   year
        return
dec_year_bcd    ;decrement date reg, check for zero underflow
                movf    year,w
                btfsc   status,z
                return                  ;underflow danger, don't decr
                call    decw_bcd
                movwf   year
        return

;*********************************************specific bcd handling routines end

;*********************************************gen. purpose subroutines follow

delay           movlw   0x001           ;standard delay routine. increase w value
                movwf   count1          ; for increased delay
                movlw   0x001           ;can set up any delay by calling delay1 (NB!)
                movwf   count2          ; with pre-set values in count1, 2, 3
                movlw   0x020           ;ex Myke Predko, piclist 4 Jan97
                movwf   count3          ;delay, (no of instructions)=
delay1          decfsz  count3,same     ;2 + 5*(count3-1) +
                goto    $-1             ;2 + (5*255 +2+5) * (count2-1) +
                decfsz  count2,same     ;2 + (5*255*256 +2 + 5*255 +2+5) *(count1-1)
                goto    $-3             ;  =
                decfsz  count1,same     ;5(count3-1)+1282(count2-1)+327684(count1-1)+6           &nb     
                goto    $-5             ;
        return                  ;

delay_25us      movlw   0x01            ;25uSec delay
                movwf   count1
                movlw   0x01
                movwf   count2
                movlw   0x06
                movwf   count3
                call    delay1
        return
delay_100us     movlw   0x01            ;100uSec delay
                movwf   count1
                movlw   0x01
                movwf   count2
                movlw   0x13
                movwf   count3
                call    delay1
        return
delay_200us     movlw   0x01            ;200uSec delay
                movwf   count1
                movlw   0x01
                movwf   count2
                movlw   0x26
                movwf   count3
                call    delay1
        return
delay_1ms       movlw   0x01            ;1msec delay
                movwf   count1
                movlw   0x01
                movwf   count2
                movlw   0xC8
                movwf   count3
                call    delay1
        return
delay_100ms     movlw   0x01            ;100msec delay
                movwf   count1
                movlw   0x4E
                movwf   count2
                movlw   0x01
                movwf   count3
                call    delay1
        return
delay_1sec      movlw   0x04            ;1 second delay
                movwf   count1
                movlw   0x0E
                movwf   count2
                movlw   0x38
                movwf   count3
                call    delay1
        return

delay_10sec     movlw   0x1F            ;10 second delay
                movwf   count1
                movlw   0x85
                movwf   count2
                movlw   0x34
                movwf   count3
                call    delay1
        return

;********************General purpose 16F84 EEPROM register read/write
;The following `eprom write' routine requires that eeadr @ loc 0x009
;in bank0 contains the address of the eeprom data byte to be loaded.
;The data must be pre-loaded in eedata @ loc 0x008 in bank0
;In addition, the  eecon1,wren   bit in bank1 regs. must be set before 
;calling this routine. Then cleared after using it.
;ie             bsf     status,rp0              & vice-versa at at finish
;               bsf     eecon1,wren
;               bcf     status,rp0

eeprom_wr                       ;write byte to eeprom loc.
        bcf     intcon,gie      ;make sure ints disabled, work on bank1
        btfsc   intcon,gie      ;to-be-suuuure
        goto    $-1
        bsf     status,rp0      ;set to bank 1,see c84 para 7.2
        movlw   0x055           ;fairy-godmother value, given by uchip
        movwf   eecon2          ;-actually for diode pump charging hv cell drives-
        movlw   0x0AA           ;another fairy-godmother value
        movwf   eecon2
        bsf     eecon1,eewr     ;set write control bit & begin write
        btfsc   eecon1,eewr     ;poll write control bit until h/w resets it LO
        goto    $-1             ;write until job done
        bcf     eecon1,eeif     ;must clear this bit, don't know why??
        bcf     status,rp0      ;bank 0
                ;enable global ints here, if using them.ie  bsf  intcon,gie
        return

;following routine requires eeadr to be pre-loaded with the eeprom location
;--like a pointer. The contents of the location are returned in eedata reg.
eeprom_rd                       ;read byte value from eeprom ->w reg
        bsf     status,rp0      ;bank 1
        bsf     eecon1,eerd     ;ee read
        bcf     status,rp0      ;bank 0
        return

inc_eeprom              ;increment eeprom regs 00,01,02
        call    read_eeprom     ;fetch all eeprom vals to 16f84 fregs   
        incfsz  samp_index1,same
        goto    inc_eeprom1
        incfsz  samp_index2,same
        goto    inc_eeprom1
        incfsz  samp_index3,same
        goto    inc_eeprom1
inc_eeprom1
        movf    samp_index1,w
        movwf   eedata
        movlw   0x01
        movwf   eeadr   
        bsf     status,rp0
        bsf     eecon1,wren
        bcf     status,rp0
        call    eeprom_wr
        bsf     status,rp0
        bcf     eecon1,wren
        bcf     status,rp0
        movf    samp_index2,w
        movwf   eedata
        movlw   0x02
        movwf   eeadr   
        bsf     status,rp0
        bsf     eecon1,wren
        bcf     status,rp0
        call    eeprom_wr
        bsf     status,rp0
        bcf     eecon1,wren
        bcf     status,rp0
        movf    samp_index3,w
        movwf   eedata
        movlw   0x03
        movwf   eeadr   
        bsf     status,rp0
        bsf     eecon1,wren
        bcf     status,rp0
        call    eeprom_wr
        bsf     status,rp0
        bcf     eecon1,wren
        bcf     status,rp0
        return

read_eeprom             ;fetch tha values of ALL eeprom 01,02,03
        movlw   0x01
        movwf   eeadr
        call    eeprom_rd
        movf    eedata,w
        movwf   samp_index1
        movlw   0x02
        movwf   eeadr
        call    eeprom_rd
        movf    eedata,w
        movwf   samp_index2
        movlw   0x03
        movwf   eeadr
        call    eeprom_rd
        movf    eedata,w
        movwf   samp_index3
        return

;**************************************************end of  g.p. subroutines

;**************************************************start of isr
service                                         ;dummy el for isr

        retfie
;**************************************************end of isr

                end