Hi,

I am trying to convert Eric Smith's sine function (
http://www.brouhaha.com/~eric/pic/sine.html ) on a 16f84. I have included the
code below. 

It does not seem to work. When I step through the code in MPLABS SINETBL is
called, but returns after the ADDWF. Then the code reaches the final RETLW and
goes back to CALL SINETBL, but does not call it, and ends up in a loop.

Any help appreciated. 


temp	EQU	0xC
zero	EQU	0xd

	; Set up: PORTA = Input PORTB = Output
	; The bitstring to be checked will be entered in PORTA
	BSF STATUS, RP0  	; Select bank 1
	MOVLW B'11111111'	; 1 to set input
	MOVWF PORTA		; Set PORTA as Input
	MOVLW B'00000000'	; 0 to set output
	MOVWF PORTB		; Set PORTB as Output
	BCF STATUS, RP0  	; Select bank 0

;***********************************************************

	GOTO START

;***********************************************************
; SUBROUTINE SECTION 
SINETBL

	ADDWF 	PCL, F	; or PCL?
	dt	000h,003h,006h,009h,00ch,010h,013h,016h
	dt	019h,01ch,01fh,022h,025h,028h,02bh,02eh
	dt	031h,033h,036h,039h,03ch,03fh,041h,044h
	dt	047h,049h,04ch,04eh,051h,053h,055h,058h
	dt	05ah,05ch,05eh,060h,062h,064h,066h,068h
	dt	06ah,06bh,06dh,06fh,070h,071h,073h,074h
	dt	075h,076h,078h,079h,07ah,07ah,07bh,07ch
	dt	07dh,07dh,07eh,07eh,07eh,07fh,07fh,07fh
	dt	07fh


;***********************************************************
; MAIN PROGRAM


START
	MOVF PORTA, 1		; Read the contents of PORTA into itself
	MOVF PORTA, W		; Move contents of PORTA into W
	MOVWF 	temp
	BTFSC 	temp,6
	SUBWF 	zero, W
	ANDLW 	07fh
	CALL 	SINETBL
	BTFSC 	temp, 7
	SUBWF	zero, w
	MOVWF	temp		; Move result to temp
	MOVF	PORTB, w	; Move result from temp to PORTB
	RETLW	0


	END			; End program



Regards,
Evan

----- End forwarded message -----



-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist