Ken Parkyn wrote:
>
> Hello all;
>
> I have programmed a PIC16C64 to act as a binary to one of 24
> decoder.
> The unit worked OK for a while, then started to output
> erratically.
> I programmed a new PIC, but it does the same.
> It worked once upon a time...anyone see what I've done wrong?
>
> code:
>
>         title   "chair"
> p=16c64
>
> PCL equ 02
> STATUS equ 03
> FSR equ 04
> PORTA equ 05
> PORTB equ 06
> PORTC equ 07
> PORTD equ 08
> PCL equ 02
> PCLATH equ 0A
> INTCON equ 0B
> OPTIONREG equ 81
> TRISA equ 05
> TRISB equ 06
> TRISC equ 07
> TRISD equ 08
> ;**************************************
> w equ 00
> f equ 01
> ADRESS equ 20
>
> ;**************************************
>
>         bsf     STATUS,5      ;go to bank 1
>         movlw   0xFF
>         movwf   TRISA   ;set port a as inputs
>         clrf    TRISB   ;set ports,b,c & d as outputs
>         clrf    TRISC
>         clrf    TRISD
>         bcf     STATUS,5      ;back to bank 0
>
> main    movf    PORTA,W ;read select address into w
>         movwf   ADRESS  ;store this in ADRESS
>         call    tableb  ;call lookup table for port B
>         movwf   PORTB   ;put result out to port B
>         movwf   ADRESS  ;restore data from ADRESS
>         call    tablec  ;call lookup table for port C
>         movwf   PORTC   ;put result out to port C
>         movwf   ADRESS  ;restore data from ADRESS
>         call    tabled  ;call lookup table for port D
>         movwf   PORTD   ;put result out to port D
>         goto    main    ;repeat
>
> tableb  addwf   PCL,f
>         retlw   01
>         retlw   02
>         retlw   04
>         retlw   08
>         retlw   10
>         retlw   20
>         retlw   40
>         retlw   80
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
> tablec  addwf   PCL,f
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   01
>         retlw   02
>         retlw   04
>         retlw   08
>         retlw   10
>         retlw   20
>         retlw   40
>         retlw   80
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
> tabled  addwf   PCL,f
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   00
>         retlw   01
>         retlw   02
>         retlw   04
>         retlw   08
>         retlw   10
>         retlw   20
>         retlw   40
>         retlw   80
>         end
>
> TIA.
>
> ________________________________________
> Ken Parkyn              email: K.Parkyn@sct.gu.edu.au
> Office of Technical Services,  Electronics Workshop
> GRIFFITH UNIVERSITY Nathan Qld.4111 Australia
> P.O.Box 185  Ph:(07)3875 7289    Fax:(07)38757151
> ________________________________________
The value stored in ADRESS at the beginning of the programm must be
restored in W with the mnemonic 'movf ADRESS,W' and you wrote 'movwf
adresse' wich make an overmemory branch when the result of the table is
80 for example .
Nice work

JEAN-PIERRE