>I started to learn programming Pic16c84?
>but can any one tell me what are the WatchDog Timer

WDT is timer, working from it's own RC-generator (if WDT turn on during the
chip's programming).
If You use WD, you MUST periodicaly clear it (by clrwdt instruction) before
timer roll-up. If it happens - you chip will be reseting.
Unfortunatly this is only software reset (goto 0), against hardware reset
(MCLR=0).
All PICs have a prescaller, tham MAY be used with WDT.
WDT period is about 22ms*Kpresc.


>and the oscillator mode HS,XT and LP ?and what is they important?

This is the internal clock genarator mode - HS for high speed cristal, XT -
for middle and LP for LOW. Of course all modes can be used with external
clock. Another mode - RC - for simple RC generator.
You MUST set clock mode during the PIC's programming.

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Alex Torres, Kharkov, Ukraine (exUSSR)
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