Re: Virtex-4FX DCM autoshutdown failure, any suggestions

Antti schrieb:

Hi

if anyone has seen the same or has any ideas how to avoid the issue I
am faced please help - I am trying to get it solved myself (my deadline
is today 21:00 german time) but kinda stuck currently.

problem:

Virtex-4FX12
2 DCMs in series
DCM1 uses only FX output for PPC system clock (to get the clock into
DLL input range)
DCM2 generates 3X clock proc clock for PPC

it all works for 360 milliseconds after configuration. then the first
DCM will remove lock, output stop, everythings stops. the delay 360
milliseconds is not dependand on the first DCM clock ratio settings. if
PPC is held in reset then the DCMs still shut down after the same 360
milliseconds.

any ideas? what to check? I have Lecroy 2GS/s DSO on some signals and
power supply lines but not seeing anything at the time where the DCM
shut off.

thanks in advance for any suggestions,

Antti

thanks for all the fine suggestions, the issue has been fixed.

Antti

.

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