Thanks Jack, Jason, I think I have the QDR Timing down now, at least in simulation.
Do I need to do anything special to use the ECC bits? If I want to calibrate QDR, does that mean I must include the CPU interface? Is this related to how I set the be flag ? Thanks, --Adam ---------------------------------------------------- Adam Schoenwald - Electrical Engineer Office: 301.286.4175 | Cell & Text: 631-241-0003 ---------------------------------------------------- -----Original Message----- From: Jason Manley [mailto:jman...@ska.ac.za] Sent: Wednesday, July 5, 2017 10:55 AM To: Jack Hickish <jackhick...@gmail.com> Cc: Schoenwald, Adam J. (GSFC-5640) <adam.schoenw...@nasa.gov>; Casper Lists <casper@lists.berkeley.edu> Subject: Re: [casper] QDR Help / Timing Diagram There's also a testbench for our ROACH2 VACC that's currently in service on MeerKAT, which may help you: https://github.com/ska-sa/cbf_fpga_testbenches/blob/master/test_qdr_vacc5.slx Note that there are calibration problems with QDR on ROACH2, so you'll likely encounter bit errors. If this matters to you, I highly recommend you leverage the ECC bits... Jason Manley CBF Manager SKA-SA Cell: +27 82 662 7726 Work: +27 21 506 7300 On 05 Jul 2017, at 16:49, Jack Hickish <jackhick...@gmail.com> wrote: > > > On Wed, Jul 5, 2017, 6:56 AM Schoenwald, Adam J. (GSFC-5640) > <adam.schoenw...@nasa.gov> wrote: > Hi All, > > I've abandoned my attempt to use the DRAM for now and moved on to QDR. > > I'm somewhat confused by the wiki at https://casper.berkeley.edu/wiki/Qdr . > > > > The "issuing commands section" says that one type of command cannot be issued > in two consecutive cycles. > > The "bursting" section says that data for both read and write is presented > for two cycles, and that data_in and be must be set for both of those cycles. > > > > Does this mean that a "write event" lasts for two clock cycles? > > If so, can data_in change from the first clock cycle to the second, storing a > total of 144 bits over two cycles? > > > Correct. I believe there is a qdr transpose block in the library which may be > a useful reference design. > > Cheers > Jack > > > > Thanks, > > --Adam > > > > ---------------------------------------------------- > > Adam Schoenwald - Electrical Engineer > > ---------------------------------------------------- > > > > > -- > 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 post to this group, send email to casper@lists.berkeley.edu. > > -- > 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 post to this group, send email to casper@lists.berkeley.edu. -- 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 post to this group, send email to casper@lists.berkeley.edu.