[casper] Problem writing to DRAM, ROACH 1

[Madden, Timothy J.]

I am using a DRAM block on a ROACH 1.

I am using python to write data to the dram with corr.

I create a binary array of zeros like:

fa.lut_binaryIQ = '\x00\x00\x00\x00\x00\x00.....'

Length of the array is 1048576.

If I do
roach.write('dram_memory',fa.lut_binaryIQ)

It works fine.

If I double the length of the binary array, where len(fa.lut_binaryIQ)=2097152

Then I do
roach.write('dram_memory',fa.lut_binaryIQ)

I get a timeout error
RuntimeError: Request write timed out after 20 seconds.


I have tried longer and longer timeouts of 60sec and still no good result. I 
set the timeout with:
roach = corr.katcp_wrapper.FpgaClient('192.168.0.67', 7147,timeout=60)


Any ideas? It seems there is a 1MB length limit on my dram.

Tim