Calvin:

Like most people said, the internal oscilator may not be a good choice because of the drift due to voltage and temperature changes.

If you must use the internal oscillator, then depending on the application of the chip, you can add some code in your program to put the chip in a test mode by holding an input low at reset time and in the test mode you can just toggle one of the outputs at a fixed rate and measure it with a frequency counter.

Shahid

----------
From:   Calvin[SMTP:tgo@CHIH1.TELMEX.NET.MX]
Reply To:       pic microcontroller discussion list
Sent:   Wednesday, February 25, 1998 4:17 PM
To:     PICLIST@MITVMA.MIT.EDU
Subject:        Internal oscilator calibration

How can the internal oscilator calibration on one of the 12C5xx pics can be
verified?

I have the original calibration value, but I would like to make sure it is
right, because my application is timing critical.

TIA

Gabriel Gonzalez