Setting 8Mhz clock speed on PIC16F684

[LEDave]

Hi Richard, thanks for the reply.

"what do you expect the result to be ?"

I thought (and was hoping) that double the OSC speed from 4 to 8Mhz would drive the led's twice as fast, 10secs would become five at 8Mhz if you see what I mean.

Dave

[LEDave]

Just to add, I based my last post on this article: http:// melabs.com/resources/pbpmanual/7_0.htm

But I may have misinterpreted it, in that I thought PAUSE 1000 with DEFINE OSC 4 internal OSC would give one second delay and pause 1000 with DEFINE OSC 8 internal OSC would give 0.5 second delay.....

So are we saying that the above PAUSE 1000 would both cause a one second delay?

Is it only external Xtals/resonators that throw the internal timing off?

Dave

[richard]

Is it only external Xtals/resonators that throw the internal timing off?

no not at all.

the only time it fails is when DEFINE OSC does not match the real osc frequency.

[LEDave]

Thanks again Richard.

So as long as I use DEFINE OSC X, PB knows and compensates for the change still giving the correct timings PAUSE etc?

David

[Dave]

Yes, That is correct. The PAUSE command is based on the OSC frequency. If you had an 4 Mhz. crystal connected and told PBP that the OSC was 8Mhz. the PAUSE command would give you 2 times the value entered into the PAUSE command.

[LEDave]

Dave & Richard, thank you both for taking the time to reply, much appreciated.

Dave