I'm just not getting this. Either my time is not being written, my clock =

is not running, or the time is not being read. (and there is no way to =

tell which it is)

Here is the PIC16 code that is supposed to work. Can anyone translate it =

to PIC18 ASM code? I've tried several times - even to the point of =

forgetting the loop and just making X read cycles, and everything is 0.

The ADD(ress) variables both start at H'B0' and the time variables run =

to H'B6'.

I know the RRFs get changed to RRCFs.

Or, as an alternative, does anyone have working ASM code for the DS1302 =

clock?

Joe M.

--------------------- start of code snippet --------------

;**********************read time program*************************
; GET_TIME
; usage: recept 7 bytes time data, sudden mode read
; INPUT:NONE
; OUTPUT:save the 7 bytes into TIME_RX_ADD's 7 registers
;*********************************************************
;input parameter: none
;output parameter:20H--26H's 7 RAMs
GET_TIME
  MOVLW B'10111111'                ;multi bytes read mode
  MOVWF TIME_TX
  BSF RST
  CALL TIME_WRITE_1
  MOVLW TIME_RX_ADD                ;save bytes
  MOVWF FSR
  MOVLW D'7'                       ;read 7 bytes continuously
  MOVWF COUNT2
TR2
  CALL TIME_READ_1
  MOVF TIME_RX,W
  MOVWF INDF
  INCF FSR,F
  DECFSZ COUNT2,F
  GOTO TR2
  BCF RST
  RETURN

;**********************write a byte program*****************
; TIME_WRITE_1
; usage: send one byte only.
; used for control word etc.
;************************************************
;input parameter=A3=BATIME_TX
;output parameter=A3=BAnone
TIME_WRITE_1
  MOVLW D'8'                      ;8 bits
  MOVWF COUNT1
TLOP
  BCF I_O                         ;the initial is low
  BCF SCLK
  BTFSC TIME_TX,0
  BSF I_O
  RRF TIME_TX,F
  BSF SCLK                        ;rise-edge to send data
  DECFSZ COUNT1,F
  GOTO TLOP
  BCF SCLK                        ;recover
  RETURN

;******************read one byte program*********************
; TIME_READ_1
; usage: read 1302 only one byte.
; schedule: receiving data when the falling edge comes, low byte first.
; according the I/o's high and low to select the shift right with or =

without carry.
;***********************************************
; INPUT:NONE
; OUTPUT:TIME_RX

TIME_READ_1
  BANK1
  BSF TRISB,4 ;                    I_O set to input
  BANK0
  MOVLW D'8'
  MOVWF COUNT1                     ;read 8 bits.
TR1
  BCF SCLK                         ;read when falling edge
  BCF STATUS,C
  BTFSC I_O
  BSF STATUS,C
  RRF TIME_RX,F
  BSF SCLK                         ;recover high
  DECFSZ COUNT1,F
  GOTO TR1
  BANK1
  BCF TRISB,4                       ;I_O recover to output
  BANK0
  BCF SCLK
  RETURN
  NOP

--------------------- end of code snippet --------------
ivp wrote:
>> Maybe I just need to change it to "INCF FSR0L,1"???
> =

>>From memory that won't increment FSR0H when FSR0L =3D 255 + 1
> =

> wbr
-- =

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