Thanks - this makes good sense now!

> -----Original Message-----
> From: vulcan@ihug.co.nz [SMTP:vulcan@ihug.co.nz]
> Sent: Thursday, May 07, 1998 5:46 AM
> To:   'pic microcontroller discussion list'
> Subject:      RE: Watchdog Timer
>
> Hi Daniel
>
> As I'm sure you have realized, OPTION is an instruction
> for the 12 bit PICs and loads the value in W into the
> OPTION register, which you can only write to.
>
> The 16C63 is a 14 bit PIC and if you wish to load something
> into the OPTION register you have to use the instruction
> MOVWF OPTION_REG.
>
> The watchdog timer is selected when you program the
> configuration word, either enabled or disabled. You can't
> stop the start or stop the watchdog timer while executing
> your code. The only thing you can do to prevent a
> watchdog time out, is the use the CLRWDT instruction
> in your code.
>
> regards
>
> Gavin
> --------------------------
> vulcan@ihug.co.nz
> http://www.geocities.com/TheTropics/Cabana/2625
> --------------------------
>
>
> -----Original Message-----
> From: Najemy, Daniel [SMTP:DNajemy@IMPS0014.US.DG.COM]
> Sent: Thursday, May 07, 1998 9:22 AM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Watchdog Timer
>
> I'm trying to use the watchdog timer on a PIC16C63.
>
> How do I turn it on?
>
> So far I'm able to write to the options register as follows:
>
> movlw   b'00001111'   ; Program WDT to 128 * .018ms = 2.3 seconds
> movwf   81h
>
> Note: For some reason I couldn't write to OPTION, the assembler did
> not
> recognize this word.
>
> I have a main loop in my program where I plan on inserting a
>
> CLRWDT
>
> to reset the watchdog....unless I"m missing a real obvious one, I
> can't
> figure out how to start this
> thing ticking!!
>
> Thanks in advance....
>
>