Hi all, I'm trying to get the QDR on the ROACH-2 to work reliably at a clock speed of a 145 MHz. I'm assuming this is possible, since it has been pointed out in an earlier message <http://www.mail-archive.com/casper%40lists.berkeley.edu/msg05736.html> that the QDR should work above 120 MHz?
I'm running the software calibration for the QDR (qdr_cal() in the qdr.py script) and the calibration seems to be successful, however after the calibration I write test patterns to the QDR but the data I read back is incorrect. What is strange is that it doesn't do it for all the test patterns, mainly for the walking 0's and pseudo random numbers, and QDR0 and QDR1 seem to be the main culprits for failure. I also don't have any QDR glitches at higher clock speeds (for instance at 200 MHz). I have been digging around and found this <https://github.com/jack-h/mlib_devel/commits/ami-devel?page=8> possible solution (see commit 72d879c). The REFCLK for the IDELATCTRL is set to a 100 MHz instead of the recommended 200 MHz. I have tried this, but I still get errors. I'm not sure if this is relevant but with this suggestion I have only found errors so far on QDR1? Does anyone have any suggestions? Thanks, JP van Rensburg
