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PWMA/SCI0 Conflict?

Started by eriley08 August 30, 2005
Hello,

I ran into an odd conflict with SCI0 and PWMA on the 56F805 and was
wondering if anyone knew anything about why it happens or what mistake
I'm making?

I'm using C (no assembler) in CodeWarrior, internal memory, 56F805 on
a NewMicros IsoPod board.

I set up SCI0 to be RS-232 9600 8N1 (there's a Maxim driver chip on
the IsoPod). It sends data successfully (only need to send for this
application, so don't know anything about receiving) after its
initialization.

I then initialize PWMA for independent edge-aligned operation. SCI0
still works fine. However, the moment I enable output pads
(un-tristate the PWM outputs; bit 15 of PMOUT), SCI0 suddenly dies and
is unable to send anything.

Using SCI1 instead of SCI0 fixed the problem, but I'm still perplexed
as to why this happens, and have had no luck finding reference to it
in the errata, the peripheral manual or the family manual.

Does anyone have any insight into or experience with this issue?

Thanks,
- Elizabeth