Hi Nikita, For finding the delay, you can record the (same) 1pps input from both the adc boards in a Bram and try to look at the delay in the rising edge between them. To do it on the fly, have a free running counter, latch the counter on the rising edge, and find the difference between the two counts, which will give the delay in clock cycles.
Thanks, Mugundhan On Wed 27 Nov, 2019 09:16 'Nikita Rathore' via casper@lists.berkeley.edu, < casper@lists.berkeley.edu> wrote: > Dear Mugundhan, > > Many thanks for your reply. > > To answer your question, yes, the same sampling clock is given to both the > ADCs from the same source (a Valon synthesizer). > > Could you please tell me how to use the 1pps signal to find the delay on > the FPGA? The design has a coarse delay before the PFB block and fine > delays after the FFT block. > > On Tue, Nov 26, 2019 at 6:35 PM Mugundhan vijayaraghavan < > v.vaishnav151...@gmail.com> wrote: > >> Hi Nikitha, >> >> Are the sampling clocks given to the adc from the same source? If you're >> giving from a different source, please check if both are synchronised. Then >> the 1pps signal can be independently be used to find the delay in the >> electronics and can be corrected for using delay blocks on the FPGA. >> >> Regards, >> >> Mugundhan >> >> On Tue 26 Nov, 2019 13:25 'Nikita Rathore' via casper@lists.berkeley.edu, >> <casper@lists.berkeley.edu> wrote: >> >>> Dear Casperites, >>> >>> I am trying to make a 4-element interferometer at L-band (bandwidth 300 >>> MHz) on a ROACH2 Board which has 2 x 5Gsps (ASIAA) ADC boards. I >>> successfully compiled and tested a 2-element interferometer, through drift >>> scans of the sun, and it yields fringes as expected. >>> >>> However, I have not been able to replicate these fringes with a >>> 4-element design, so I started testing a 2-element correlator using two >>> different ADCs on the same ROACH2. I was earlier using a software >>> synchronization, as suggested in the tutorial. >>> >>> Could you please guide me on how to synchronize the two cross ADC of the >>> same ROACH2 Board so they can be in sync with the FPGA clock (150MHz) which >>> is taken from one of the ADC clocks (adc0 in my case). We have used two >>> ADC1x5000-8 of the board for the experiment. We noticed the two sync port >>> on the Board and as mentioned on the Casper site we had synchronized our >>> ADC by 1pps signal and also by software. I have attached the results. >>> >>> My question is how to synchronize these two ADC by a pps signal and also >>> do we need to synchronize the cross ADC of the same Board when working for >>> correlator. In my case, I had the same results for synchronized and >>> unsynchronized ADC. >>> Synchronization of two cross ADC >>> <https://docs.google.com/a/iiti.ac.in/document/d/1fdzVWFTYx55IftxvvgSxvJfFk9x1Q89-Gum2iukoVpo/edit?usp=drive_web> >>> >>> >>> -- >>> Nikita Rathore >>> Junior Research Fellow >>> Discipline of Astronomy, Astrophysics & Space Engineering (DAASE) >>> Indian Institute of Technology, Indore >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "casper@lists.berkeley.edu" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to casper+unsubscr...@lists.berkeley.edu. >>> To view this discussion on the web visit >>> https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAOvmUY5%3D9XcjrDBigY4Gz2TkxeCONcZA2dciTeRgE%3DVbeqBB0Q%40mail.gmail.com >>> <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAOvmUY5%3D9XcjrDBigY4Gz2TkxeCONcZA2dciTeRgE%3DVbeqBB0Q%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "casper@lists.berkeley.edu" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to casper+unsubscr...@lists.berkeley.edu. >> To view this discussion on the web visit >> https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAD560xn0AkOn4%2B%2BcWo9jwhw1g5332kjMKhjh%3DA6967qq5ENU%2BQ%40mail.gmail.com >> <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAD560xn0AkOn4%2B%2BcWo9jwhw1g5332kjMKhjh%3DA6967qq5ENU%2BQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > Nikita Rathore > Junior Research Fellow > Discipline of Astronomy, Astrophysics & Space Engineering (DAASE) > Indian Institute of Technology, Indore > > -- > You received this message because you are subscribed to the Google Groups " > casper@lists.berkeley.edu" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to casper+unsubscr...@lists.berkeley.edu. > To view this discussion on the web visit > https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAOvmUY4A1_Ez3bnN6LNxx9buz8L0pMy0qzXrVib3R5Q%2B%2BS%2B_%2BA%40mail.gmail.com > <https://groups.google.com/a/lists.berkeley.edu/d/msgid/casper/CAOvmUY4A1_Ez3bnN6LNxx9buz8L0pMy0qzXrVib3R5Q%2B%2BS%2B_%2BA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu" group. 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