USB Internal Oscillator Setting

[Keith55555]

I've used the serial programmer for some time and now have the usb programmer. The old GUI had "internal oscillator". The new one has two choices for internal: 'INTOSC clockout' and 'INTOSCIO'. I can't find the description of these. Simply want to use the internal oscillator on a 16F672. Thanks, Keith

[Darrel Taylor]

Hi Keith,

I don't think Microchip makes a 16F672.
Maybe you meant the 16F627.

At any rate, the difference between the two options relates to the OSC2 pin.

'INTOSC clockout' would put out FOSC/4 on the OSC2 pin continuously.
A 4Mhz internal OSC will produce a 1Mhz output on OSC2.

Plain 'INTOSC' allows both the OSC1 and OSC2 pins to be used as general I/O.

[Keith55555]

Thanks Darrel. Yes, '627; that'll teach me to rely on my memory now only enough room for logic decisions.
Thanks for that info. Couldn't find source for it.-Keith

[Darrel Taylor]

The place to look is in the 627's datasheet section 14-11 CONFIGURATION WORD.
For the oscillator selection (bit4, 1-0) you'll see this ...



Then a little further down (14.2.7) it says what CLKOUT means.



HTH,