Tom=E1s =D3 h=C9ilidhe wrote:

> I'm used to using the 16F684, and I had the following macro for getting =

> the greatest speed out of it:
> =

>     #define CrankTheSpeed() ((void)(OSCCON |=3D 0b1110000,OSCTUNE =3D 0b1=
111))
> =

> I got myself a "Pickit2 Debug Express" today though, and from now on =

> I'll be working with the 16F887.
> =

> I took a quick glance at the datasheet for the 887 and it tells me that =

> the max speed I'll get is 8 MHz if I choose to use internal oscillators.
> =

> I want the absolute maximum speed though (so I think that means I use an =

> RC circuit to tell it what speed I want).
> =

> Could someone please explain to me what pin I put the RC on, what RC =

> values to use, what registers to set, etc.?
> =


Exactly *why* do you want a RC osc (or the INTOSC)
instead of the usual crystal+caps ??

And, btw, the 684 and the 887 are similar
when it comes to OSCCON and OSCTUNE, so no
difference there. You'll get more or less
the same performance from both.

If you need more performance with *no* external
RC or crystals, use one of the PIC18's with
8 Mhz INTOSC and 4*PLL for a 32 Mhz effective
*internal* oscillator.

 > > Could someone please explain to me what pin I put the RC on...

*That*, and the other related qustions, are clearly an
area where the datasheet is the *PERFECT* source for
the answer.


Regards,
Jan-Erik.
-- =

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