packet formation and convolution coding..single ended to external lvds on actel fpga

Hi..
I have designed a program which packetizes data and performs convolution coding in actel fpga A3P1000,
i have converted the single ended output i q and clk to differential output within fpga, the program runs fine.
On the second board I then used the single ended output and used an external lvttl to lvds convertor. the output is transmitted to the microD connector to decode it on matlab. I get the desired frames sometimes and sometimes I don't. can anyone tell me what can be the issue? The hardware is fine. the matlab code is perfect. the external Tranceivers are all ok. the board is perfect.

incisive29 said:

I get the desired frames sometimes and sometimes I don't. can anyone tell me what can be the issue? The hardware is fine. the matlab code is perfect. the external Tranceivers are all ok. the board is perfect.

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Uh, obviously something is NOT perfect. First rule of debugging, suspect anything could be wrong, then prove one-by-one something is absolutely not wrong (this is the hard part).

I've noticed that the people that are the worst at debugging are the ones with lots of ego, that always think the problem is NOT in their stuff.

The times it's taken me the longest to find a problem have always been when I take at face value, another engineer instance that they have checked out their stuff and it's doing everything correctly...and I don't look at their stuff. It usually ends up the problem is in the interface between their stuff and mine. Things like a signals that suddenly change timing/protocol intermittently so my design can't capture the data (as it now violates the interface timing/protocol, which I got from them in the first place :bang.