Hi Xavier, The only yellow block info you'll find is by looking at the code. When configured properly for a given mode, the block doesn't time multiplex multiple ADC channels, it does what you expected it to do. I just checked the init code we use for HERA, and it's pretty much the same as you, though we use inputs 1 and 3 (adc.selectInput([1,1,3,3]). I'm not sure if this is significant (I don't think it should be). What version of casperfpga are you using? Cheers Jack
On Wed, 4 Sep 2019 at 09:18, Xavier Bosch <[email protected]> wrote: > > Hi all, > > I been using SNAP board (a regular-standard board) for a while now in a 3-ADC > @ 800 MHz configuration mode. I would like to use it in a 6-ADC @ 500 MHz > configuration mode and I am having some trouble understanding what is going > on. I read the HMCAD1511 datasheet. > > ADC configuration with [1,1,2,2] (see the whole ADC calibration function at > the end of this email) > > I connected a snap block (dataloggers) to the yellow-block (snap_adc) to > record time series of the collected data. What I see is that ADC0 and ADC1 > outputs are not spitted between a0 and a1 (yellow block) and a2 and a2, > respectively. > Instead, what I find is that they are time multiplexed, ie. at t0 I have that > ADC0 is at a0, a1, a2 and a4, and at t1 I have ADC1 at a0, a1, a2 and a4 > > See attached picture of 8 consecutive samples of a0, a1, a2 and a3 with only > ADC0 connected (figure ADC0_ch0) and then ADC0 and ADC1 connected > (Figure_ch0_ch1), ie. First row is t0, second row is t1) > > The HMCAD1511 datasheet does not show a time multiplexed output but a > parallel output. I do not know how the yellow block is implemented. Where I > could find more information about the yellow block implementation? > Is that the expected yellow block output? If the yellow block time > multiplexes the ADC0 and ADC1 then how do you synchronize the channels with > the rest of the design? > > > code that I use to configure/calibrate the ADCs > > def init_adc(self): > > self.sample_rate=500 > > adc = casperfpga.snapadc.SNAPADC(self.fpga,ref=50) > > if adc.init(self.sample_rate, numChannel=2,resolution=8) == 0: > > print "ADC calibrated! " > > else: > > print "ERROR ->>> ADC NOT calibrated! " > sys.exit(0) > > #adc.selectADC(0) > > adc.adc.selectInput([1,1,2,2]) > > > > Best, > > XB > > > > > > -- > 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/CAMehrA33bgtX2u_tAA0fQLsh7FbmeAMx1y%3DRDQ%2BmB79fTKFOJw%40mail.gmail.com. -- 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/CAG1GKSmiv_Ci%3DU88PoECMM8b_AcWWCvmCqSggyQB5RXJV9twQw%40mail.gmail.com.
