I wrote: > Please don't read too much into the little waves that ride on > top of the curve. They're just ambient RF pollution.
Joerg suggested that this may be reflections. So I tried again with a probe that's less noise-prone: These two waves with maximum drive strength show a quiet moment ... http://people.openmoko.org/werner/mmc_drive_max_quiet.png ... two noisier moments ... http://people.openmoko.org/werner/mmc_drive_max_bounce3.png http://people.openmoko.org/werner/mmc_drive_max_bounce4.png ... and a mixed result with minimum drive strength: http://people.openmoko.org/werner/mmc_drive_min_both.png Since the amplitude of that ~100MHz noise varies somewhat with the drive strength, reflections seem to play a part. But most of it is probably just FM radio I pick up. The important bit is still that the clock edges change speed, which can now be seen more clearly. - Werner
