I happen to be checking the clock output of a Atmel ATiny 9.
I seem to get a different frequency reading depending on the collection time. If I collect for 500ms the frequency reading is about what I would expect 8Mhz.
If I collect for 1ms the frequency for the whole trace is 1.4Mhz. But if I do a ruler measurement over about 90% of the trace I get 8Mhz again.
Why the difference and what am I over looking? I have uploaded images of the scope.