Hi, Danny, If you have its dependencies installed, the adc16_plot_taps.rb script can be useful for showing the deskew stuff. The sync errors seem really strange. What is the ADC clock frequency? Have you tried swapping ADC clock cables between a “good” ROACH2 and a “bad/marginal” ROACH2?
Dave > On Nov 4, 2015, at 3:07 PM, Danny Price <[email protected]> wrote: > > Hi all > > We are seeing some errors where our ADC16x250 cards don’t seem to be > completing SERDES calibration successfully when programmed (using the > adc16_init.rb script). > > Running the adc16_status.rb script we see errors like this: > > rofl1: Design built for ROACH2 rev2 with 8 ADCs (ZDOK rev2) > rofl1: Gateware does not support demux modes > rofl1: ZDOK0 clock OK, ZDOK1 clock OK > rofl1: AAAABBBBCCCCDDDDEEEEFFFFGGGGHHHH > rofl1: 12341234123412341234123412341234 > rofl1: .............................XX. deskew > rofl1: .....XXX.....X...............XX. sync > > Interestingly, out of our 16 roach2 boards, it seems to only/mainly affect > boards #1 and #7. The FPGAs themselves seem to be clocking correctly, and > we’re reasonably sure that we have good clock signal distribution. > > Iteratively reprogramming the roach we can eventually get these boards to > calibrate successfully, but it takes multiple trials. > > Any ideas of things to check/consider? > > Thanks > Danny
