This sounds like skating on thin ice to me.  I would avoid it.  Maybe what
you really want to do is trigger a watchdog timeout, and restart the PIC for
real?

--Lawrence

----- Original Message -----
From: "James Hillman" <james@IND-INTERFACE.CO.UK>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Monday, February 25, 2002 3:15 AM
Subject: [PIC]: is it ok to have stack underflow ?


> In my 16F628 program I call a subroutine that waits for an event to
happen.
> If the event does not happen within a certain length of time can I use a
> goto instruction to restart the program from a known point, without using
a
> return instruction to pop the return address back off the stack ?
> I know this will cause a stack underflow(?) condition, but since the stack
> is a circular buffer surely it won't matter because subsequent calls will
> have the required return to go with them - or will it ?
>
> Start:
>      call initialize
> StartEnd:
>      call setup
> Mainloop:
>      call Subroutine
>      call sub2
>      goto Mainloop
>
> Subroutine:
>      clrf counter
> SubLoop:
>      btfss Input1
>      retlw 0x00
>      btfss Input2
>      retlw 0x01
>      decfsz counter,f
>      goto SubLoop
>      goto StartEnd             ;timeout so restart again
>
> Thanks,
>
> James
>
> --
> http://www.piclist.com hint: To leave the PICList
> mailto:piclist-unsubscribe-request@mitvma.mit.edu
>
>

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu