Quote Originally Posted by cotang
I just wondering how fast of a clock speed I need to get 1us or 0.5us resolution.
I would guess 40MHz and 80MHz respectively.

Guess based on the fact that it must take a minumum number of cycles to execute and the product of Clock in MHz and Resolution in uS seems to remain contant eg

4 * 10 = 40
20 * 2 = 40

therefore

40 / 1 = 40
40 / 0.5 = 80

I also think that 8Mhz would give 5uS resolution

40 / 8 = 5