Progress update. The board is currently clocked at 256 and its mining at 3.6 GH/s. See
https://bitcointalk.org/index.php?topic=198489.msg2712124#msg2712124WU: ~55/m. Error rate is really low too.
I still don't know what happened. I mentioned periods of total inactivity that I was noticing in the log file. I tried to debug it and realized that there was some kind of locking conflict while writing to the USB. I didn't change anything, was just trying to log additional information. Added a few lines of code to log in logging.c and miner.h. Tried to run again, and there were no conflicts anymore. Will look at everything again tomorrow and try to pin point the issue.
Great to see this!
I am having the same problem with CGMiner as you mentioned before. I am having 4 chips working. The same 2 NOR gates trick as BBKCoins suggested and the RC values are 100Ohm and 220pF.
I have tested the board with "ww" in ktest, it always return "GOOD" from 128MHz to 300MHZ and the return time is always correct as expected.
However, when I run CGMiner, it's stuck for up to 1 or 2 minutes from time to time and the hashing rate is always much lower than expected (128M WU=4/m, 300M WU=7.1/m). And the HW is very high 10-20%.
I have tested it with different pools, all give the similar results.
I am going to change the 220pF capacitor to 30pF and test it again.
Yea I was having the exactly same issue. It has disappeared magically. Maybe the logging code I added, created a little delay and thats why the lock conflicts disappeared. Try adding some delay before wr_lock around line 1500 in usbutils.c
I hardly get any good nonce if I clock it over 279. I have the exact same circuit as provided by BkkCoins. The only difference is that my capacitor is 33pF, instead of his 30pF.