With regards to the demux option, for the system you describe you want -d 2 (I.e. demux by = run the FPGA at half the sample rate, and process two samples in parallel on every FPGA clock cycle). Basically, provided you have the up to date ruby package, all you need to do is run adc16_init.rb with appropriate options, and that will program your roach and set everything up for you.
I think the default mode of the adc16 ruby script assumes that, whatever mode you're using the ADC in, the external clock provided is at the sample rate. Though, as Matt added, the ADC supports other dividing options if they're useful to you and you're willing to read the ADC data sheet to work out how to set the divider properties. Cheers Jack On Wed, 9 Mar 2016, 09:49 David MacMahon, <dav...@astro.berkeley.edu> wrote: > Hi Vishwa, > > I am not at my computer right now, so this is from memory, but I think you > want to specify an IP clock rate of 240 MHz and supply a 480 MHz clock to > the ADC card(s). The IP clock rate is sometimes called the fabric clock > rate. It is the rate at which the FPGA logic elements (aka fabric) operate. > The ADC chips need a sample clock that is commensurate with the sampling > frequency. When you initialize the ADCs using adc16_init.rb, be sure to > pass the "-d" option. If your version of adc16_init.rb does not support the > "-d" option, then you will need to update it. > > Hope this helps, > Dave > > On Mar 9, 2016, at 08:33, Vishwa Seneviratne <mp...@zips.uakron.edu> > wrote: > > Hi David/Jack, > > We are working on a beam former and we use the 'ADC16x250-8 coax rev 2' to > sample RF signals using ROACH2-Rev 2. The operating BW is 240MHz. Thus, we > need to sample the signals at 480 MSamples/s. We have few queries regarding > the adc16 yellow block and how to setup the input clock. > > 1. Can we compile a design by setting the IP clock rate to 480MHz? > 2. Should we supply a IP clock frequency of 480MHz to the ADC board to > achieve a sampling rate of 480MSamples/s. If not, at what clock rate > should we supply? And what other parameters needed to setup when running > the bof file. > > Thank you > > > Sincerely, > > > *Vishwa Seneviratne* > > *Graduate Student* > > *Dept. of Electrical and Computer Engineering* > *University of Akron* > > On Wed, Feb 3, 2016 at 12:38 PM, David MacMahon <dav...@astro.berkeley.edu > > wrote: > >> Hi, Vishwa, >> >> The software installed by following the ADC16 user guide had not been >> updated with the newer version of the adc16 code that supports demux mode. >> I have updated the software that the user guide points to, so if you >> reinstall the adc16 gem as per the user guide you should get version 0.4.0 >> which supports demux mode. >> >> Thanks for bringing this issue to my attention. >> >> Dave >> >> On Feb 3, 2016, at 7:02 PM, Vishwa Seneviratne <mp...@zips.uakron.edu> >> wrote: >> >> Hi Dave, >> >> Here is the output. >> >> vishwa@server3:~/Desktop/roach/poly$ adc16_init.rb -h >> Usage: adc16_init.rb [OPTIONS] HOSTNAME BOF >> >> Programs HOSTNAME with ADC16-based design BOF and then calibrates >> the serdes receivers. >> >> Options: >> -i, --iters=N Number of snaps per tap [1] >> -r, --reg=R1=V1[,R2=V2...] Register addr=value pairs to set >> -v, --[no-]verbose Display more info [false] >> -h, --help Show this message >> >> >> vishwa@server3:~/Desktop/roach/poly$ gem list adc16 >> >> *** LOCAL GEMS *** >> >> adc16 (0.3.6) >> >> >> >> >> Sincerely, >> >> >> *Vishwa Seneviratne* >> >> *Graduate Student* >> >> *Dept. of Electrical and Computer Engineering* >> *University of Akron* >> >> On Wed, Feb 3, 2016 at 11:28 AM, David MacMahon < >> dav...@astro.berkeley.edu> wrote: >> >>> What does "adc16_init.rb -h" show? What does "gem list adc16" show? >>> Maybe you need a newer version of the adc16 code. >>> >>> Dave >>> >>> On Feb 3, 2016, at 18:20, Vishwa Seneviratne <mp...@zips.uakron.edu> >>> wrote: >>> >>> Hi Jack, >>> >>> I'm thinking that the ruby script 'adc16_init.rb' does not identify the >>> '--demux' parameter. I used the code at 'git:// >>> github.com/david-macmahon/casper_adc16.git'. What can I do to set the >>> parameter? >>> >>> Thank you >>> >>> >>> Sincerely, >>> >>> >>> *Vishwa Seneviratne* >>> >>> *Graduate Student* >>> >>> *Dept. of Electrical and Computer Engineering* >>> *University of Akron* >>> >>> On Wed, Feb 3, 2016 at 11:02 AM, Vishwa Seneviratne < >>> mp...@zips.uakron.edu> wrote: >>> >>>> Hi Jack, >>>> >>>> I did try all the combinations. The error remains the same. >>>> >>>> $ adc16_init.rb -v --demux=1 192.168.10.5 poly_design.bof >>>> /var/lib/gems/1.9.1/gems/adc16-0.3.6/bin/adc16_init.rb:40:in `<top >>>> (required)>': invalid option: --demux=2 (OptionParser::InvalidOption) >>>> from /usr/local/bin/adc16_init.rb:19:in `load' >>>> from /usr/local/bin/adc16_init.rb:19:in `<main>' >>>> >>>> >>>> Sincerely, >>>> >>>> >>>> *Vishwa Seneviratne* >>>> >>>> *Graduate Student* >>>> >>>> *Dept. of Electrical and Computer Engineering* >>>> *University of Akron* >>>> >>>> On Wed, Feb 3, 2016 at 2:25 AM, Jack Hickish <jackhick...@gmail.com> >>>> wrote: >>>> >>>>> Hi Vishwa, >>>>> >>>>> Is the syntax definitely -demux=1 andnot either --demux=1 or -d 1 ? >>>>> >>>>> >>>>> Jack >>>>> >>>>> On Wed, 3 Feb 2016, 12:39 a.m. Vishwa Seneviratne < >>>>> mp...@zips.uakron.edu> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> I am working on how to work with different operating of >>>>>> the 'ADC16x250-8 coax rev 2' for a very simple design to test how the ADC >>>>>> works. The design is compiled at an IP clock rate setting of 200MHz. My >>>>>> objective is to sample my input signal at higher sampling rate >>>>>> (preferably >>>>>> 400, 800 MHz). >>>>>> >>>>>> According to the user guide '' >>>>>> https://casper.berkeley.edu/wiki/images/4/4c/ADC16_user_guide.txt"; >>>>>> by setting the demux parameter I should be able to switch between >>>>>> different >>>>>> sampling rates. I get the following error. >>>>>> >>>>>> $ adc16_init.rb -v -demux=1 192.168.10.5 poly_design.bof >>>>>> /var/lib/gems/1.9.1/gems/adc16-0.3.6/bin/adc16_init.rb:40:in `<top >>>>>> (required)>': invalid option: -demux=2 (OptionParser::InvalidOption) >>>>>> from /usr/local/bin/adc16_init.rb:19:in `load' >>>>>> from /usr/local/bin/adc16_init.rb:19:in `<main>' >>>>>> >>>>>> When I don't pass the 'demux' parameter the ADC board get initialized >>>>>> to 8 analog inputs by default. >>>>>> >>>>>> How do I resolve this issue? or how can I set the ADC's to operate at >>>>>> different sampling rates? >>>>>> >>>>>> Thank you in advance >>>>>> >>>>>> Sincerely, >>>>>> >>>>>> >>>>>> *Vishwa Seneviratne* >>>>>> >>>>>> *Graduate Student* >>>>>> >>>>>> *Dept. of Electrical and Computer Engineering* >>>>>> *University of Akron* >>>>>> >>>>> >>>> >>> >> >> >
