Peek Poke pic16f870

[paul borgmeier]

Eric,

This will get you closer - I maintained your logic exactly, which, looks to me, to be a bit troubling as SKIMASK noted. You also will want to get a copy of the 16F870 datasheet to go with the manual. Email back if you want more.

;symbol cmcon=$1f	; 16F870 has no comparators and $1f is ADCON0 not CMCON
;poke cmcon,7	; this line and above not needed for the 18F870
;symbol adcon0=$9f  ; $9F is ADCON1 not ADCON0 – these two lines repeat the next two
;poke adcon0,7
symbol adcon1=$9f
poke adcon1,7	; Make all of PORTA Digital rather than analog

Poke, $85, %00000011	; make pins 0 and 1 on PORTA inputs, the rest outputs
Poke, $87, %00000011	; make pins 0 and 1 on PORTC inputs, the rest outputs
Poke $86, %00000000    	  ; make all of PORTB outputs
Poke $05, 0			; make all outputs of PORTA low
Poke $06, 0			; make all outputs of PORTB low
Poke $07, 0			; make all outputs of PORTC low

start:
peek 5, B0			; read PORTA into predefined variable B0
if bit0=0 then A		; if B0.0 = 0 then GOTO A (no gosub in if statement)
ReturnFromA:
if bit0=1 then D		; if B0.1 = 1 then GOTO D (no gosub in if statement)
ReturnFromD:
peek 7, B1			;  Read PORTC into B1
if bit8=0 then B		; if B1.0 = 0 then GOTO B
ReturnFromB:
if bit8=1 then C		; if B1.0 = 1 then GOTO C
goto start

A: low 6: high 7	; make PORTB pin 6 low and pin 7 high
Goto ReturnFromA

B: low 4: high 5	; make PORTB pin 4 low and pin 5 high
ReturnFromB
C: low 7		; make PORTB pin 7 low
Goto Start
D: low 5  		; make PORTB pin 5 high
Goto ReturnFromD
END

oh, I have not tried this - I do not use PBC anymore ... and you might want to start your project by trying to blink and LED or two rather than trying to code a complete program.