On Tue, Jun 18, 2002 at 06:31:03PM -0400, Sivaram M Cheekiralla wrote:
> Hi,
>    Can anyone tell me how to use the internal oscillator in the
> PIC(16F84A).

Sivaram,

There is no internal oscillator in the PIC 16F84A. That's one of the reasons
why it's fast becoming obsolete.

> I am new to the PIC programming, so please don't mind if my
> question is too trivial.

Not trivial at all. But before proceeding further I'd suggest taking a read
of my 16F84A/16F628 comparison:

http://www.finitesite.com/d3jsys/16F628.html

Which discusses you internal oscillator issue, i.e. the 16F84A doesn't have
one and the 16F628 does.

And in preparation for the inevitable 16F628 question about its internal
oscillator you need to set bit 4 of the config word to a (1) and set bits
1 and 0 of the config word to either (01) if you want the output clock
frequency on RA6 or (00) if you want RA6 as a I/O pin.

Lastly bit 3 of the PCON register (address 0x8E) is the OSCF bit and controls
dual speed of the oscillator.

Hope this helps,

BAJ

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