Hello Charles,

The required accuracy and stability of a counter timebase depends very much on what you want to do with it.

From Raghu's post it is clear that he is using a 16-bit counter, which gives a resolution of 15 ppm. Almost any 'run-off-the-mill' crystal oscillator will be stable enough to give meaningful results at this resolution and there is really no need to spend hundreds of dollars on the ultimate in accuracy and stability.

The article you mentioned can be found here. It's a 796K file, but well worth downloading!

Regards,
Rob.