On Tue, 2009-06-16 at 11:27 +0000, crustypaul wrote:
> One thing that might show a problem is that while pin 20 of the
> MSM5232 (CLK1) shows the correct clock input on my scope, at pin 19
> which is meant to be CLK2 and have the same waveform all i'm getting
> is a constant +5V or so.
Oooh, okay. Does this change when you pull the MSM5232?
CLK1 and CLK2 are generated by IC17 and IC18 at points J and K. Going
by the diagram they should be 1MHz squarewaves, possibly with a bit of a
phase shift between them. Until I sit down and get a proper look at
what's going on with IC17, 18, 19 and 20 I can't really say what all
that is, but it looks like it uses the flipflop to maybe introduce a 90
degree phase shift for the clocks.
Anyway, one of them being a steady 5V isn't good.
Gordon