Thanks for the help everyone.  The stupid mistakes you make when you're
tired!!!!

Stew


> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf
> Of PicDude
> Sent: 22 June 2006 04:38
> To: Microcontroller discussion list - Public.
> Subject: Re: [PIC] Overwriting Previous Address Contents
> 
> "org 0" says to start placing those instructions at code address 0, and
> subsequent instructions at addresses 1, 2, 3, 4, 5, etc.  Later, you use
> "org
> 4", telling the assembler to start placing those instructions in location
> 4,
> which is already occupied.  So it's telling you that it's overwriting the
> previous address contents.
> 
> After "org 0", you should tell it to "goto" some other location or "call
> some
> other routine" where you have more space for code.
> 
> Take a look at the ".LST" file that the assembler creates, as it will show
> you
> where each instruction is placed in the address space.
> 
> Cheers,
> -Neil.
> 
> 
> On Wednesday 21 June 2006 08:13, Stewart Abel wrote:
> > I have written the following code for a PIC16f73:
> >
> > INCLUDE "p16f73.inc"
> >
> >  CBLOCK 0x020
> > 	_w, _status, ins, pins, inres
> >  ENDC
> >
> > 	 PAGE
> >
> >  org 0
> >
> > 	nop
> > 	clrf	PORTB
> >
> > 	bsf		STATUS, RP0
> > 		movlw	0x070
> > 		movwf	TRISB
> > 	bcf		STATUS, RP0
> >
> > 	movlw	0x088
> > 	movwf	INTCON
> > 	movlw	0x00C
> > 	movwf	PORTB
> >
> > 	movfw	PORTB
> > 	movwf	pins
> >
> > 	goto 	mainline
> >
> >
> >  org 4
> >
> > Int
> > 	movwf	_w			; Save Status register prior to
> > Interrupt Handler
> > 	movf	STATUS, w
> > 	movwf	_status
> > 	movfw	PORTB
> > 	movwf	ins
> >
> > 	bcf		INTCON, RBIF
> >
> > 	xorwf	pins, w
> > 	movwf	inres
> > 	btfsc	inres, 4
> > 		goto Forward
> > 	btfsc	inres, 5
> > 		goto Reverse
> >
> > 	goto Stop
> >
> > Forward
> > 	movlw	0x00A
> > 	movwf	PORTB
> > 	goto	IntEnd
> >
> > Reverse
> > 	movlw	0x005
> > 	movwf	PORTB
> > 	goto	IntEnd
> >
> > Stop
> > 	movlw	0x003
> > 	movwf	PORTB
> >
> > IntEnd
> > 	movfw	ins
> > 	movwf	pins
> > 	movf 	_status, w	; Restore Status Register
> > 	movwf	STATUS
> > 	swapf	_w, f
> > 	swapf	_w, w
> >
> > 	retfie
> >
> > mainline
> > 	goto $
> >
> > 	end
> >
> >
> > When I try to build it I get the following errors
> >
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 33 : Overwriting previous
> > address contents (0004)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 33 : Overwriting previous
> > address contents (0004)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 34 : Overwriting previous
> > address contents (0005)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 34 : Overwriting previous
> > address contents (0005)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 35 : Overwriting previous
> > address contents (0006)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 35 : Overwriting previous
> > address contents (0006)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 36 : Overwriting previous
> > address contents (0007)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 36 : Overwriting previous
> > address contents (0007)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 37 : Overwriting previous
> > address contents (0008)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 37 : Overwriting previous
> > address contents (0008)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 39 : Overwriting previous
> > address contents (0009)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 39 : Overwriting previous
> > address contents (0009)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 41 : Overwriting previous
> > address contents (000A)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 41 : Overwriting previous
> > address contents (000A)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 42 : Overwriting previous
> > address contents (000B)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 42 : Overwriting previous
> > address contents (000B)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 43 : Overwriting previous
> > address contents (000C)
> > Error[118]   C:\PIC PROJECTS\MOTOR\MOTOR.ASM 43 : Overwriting previous
> > address contents (000C)
> >
> > I cant work out what is wrong.  An anyone shed any light.
> >
> > Cheers
> > stew
> --
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