Hi, Sorry to repost this. Just curious if anyone has experience using more than 256 MB of FPGA DRAM on the ROACH, in particular through the PPC interface.
Thanks, Glenn On Wed, Feb 12, 2014 at 12:44 PM, G Jones <glenn.calt...@gmail.com> wrote: > Hi, > I'm using the ROACH 1 DRAM for a lookup table for waveform generation with > the DAC. Everything has been working well and as I expected, until I tried > to use more than 256 MB. It looks like the ROACH has a single sided 1 GB > DRAM module in the FPGA DRAM slot, but I don't have the exact part number > (it came as shipped from Mo). I figured I might only be able to use 512 MB > because of the caveat listed on the DRAM wiki page: > "Many ROACHs have been shipped with 1 GB dual rank DIMMs by default. The > current DRAM controller is not able to handle multiple ranks, so when a > dual-rank DIMM is installed on the board, only half the memory is > available. In order to use the full 1 GB, a single rank DIMM is needed, or > in principle a dual rank 2 GB module." > > But I was surprised to have issues passed 256 MB. Has anyone seen anything > like this before? Is it a known issue? > > Thanks, > Glenn >
