Hi Tim, Unfortunately this *is* a common issue with the SNAP ADC and the current calibration code, but it is non-critical.
To the best of my understanding, it has to do with the way the individual lanes for each ADC core are aligned. Because there are multiple windows in which there are no errors for each lane individually, it's possible for the lanes to end up in a situation where they work singularly, but not together, hence failing the final ramp test. The simplest solution I've found in the interim is just to put the ADC calibration in a loop. It's rare for a board to get into this state multiple times in a row, so a loop of a few times will solve the problem, if not in the most elegant way! As a side note, Aaron Parsons recently rewrote parts of this code to be python 3 compatible, and in the process made the calibration much faster. We're looking into integrating that into the main casperfpga repo, and I'll take another look at finding a proper way to fix this particular problem as we do (it may be that we should just internalize the loop...). Hope this helps, Jonathon On Thu, 17 Dec 2020 at 15:15, 'Timothy Bateman' via [email protected] <[email protected]> wrote: > Hi all, > > I'm using SNAP boards and at times we are having random ADC calibration > issues on several boards that just go away: > > Using config file: config/correlator_m12_f8/s06.scfg > Connected to SNAP > Upload and program ../firmware/bofs/um2d_2020g_2020-05-16_1637.fpg... > Initialize ADCs... > ERROR:casperfpga.snapadc:ADCs failed on ramp test. > ADC CALIBRATION ERROR > > Any insight into what can cause the error ? Is this a common issue ? > > Thanks Tim > > -- > You received this message because you are subscribed to the Google Groups " > [email protected]" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/SYBPR01MB46203DE59DC351714A839505A2C40%40SYBPR01MB4620.ausprd01.prod.outlook.com > <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/SYBPR01MB46203DE59DC351714A839505A2C40%40SYBPR01MB4620.ausprd01.prod.outlook.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "[email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAPU71P_zNbw2cE0xfyFeJx%2BU05AzdVrsOA-Bdwq-A9O5uLzEJA%40mail.gmail.com.
