Hi
I saw the post on this group for editing a spartan-2 bitstream. I was looking into a way of changing the frequency multiplier and divider values of a DCM while downloading the bitstream (to support variable sampling rate for my application). As I understand those values cannot be changed after loading the bit stream. Has anybody done something like that ?
Sumit
Sumit,
We do it all the time here in the lab(for testing).
You have to find the M and D values (just do a diff on two bistreams where that is the only change), and then disable the CRC check (in bitgen).
In V4 we have the dynamic reconfiguration port (DRP - an 8 bit uP like interface port to talk to the DCM config bits) for the DCM which allows changes while operating. RESET must be asserted in order to re-lock however.
Aust> Hi
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