I am trying to use the cellular ram on the Nexys 4 FPGA development board. I am using Xilinx Vivado and would like a Microblaze soft core processor to be able to perform reads and writes. So far I have created the processor in a block design.

After much hunting through the internet I eventually found an external memory controller or EMC which I thought looked promising. How would I go about connecting the Ram up? I have created a HDL wrapper and tried connecting the ports of the EMC to the pins of the ram, however, there are more ports than I need. I can't find any examples of the Nexys 4 or for the Vivado EMC.

I also found that the Nexys 2 has an example of an onboard memory controller. I see that the part number is the same for the RAM. Would this be usable and how would I use it in conjunction with the Mircoblaze?

  • \$\begingroup\$ Sure thing, I would have posted it before but I can only post two links in the question because I have less than 10 reputation. Here you are. Its the 128Mb one. \$\endgroup\$
    – Marmstrong
    Commented Feb 11, 2014 at 14:16
  • \$\begingroup\$ Update: Still haven't been able to succeed in this venture. First of all there is a bug withing Vivado 13.4 which stops the BMM (Block Ram Memory map) from being seen as it assigns it a different name to the top level code. Still haven't got a work around for it but it's in progress. In relation to the extra ports of the EMC, I wired them to unused headers. I will keep this question posted on my progress. \$\endgroup\$
    – Marmstrong
    Commented Feb 18, 2014 at 14:23
  • \$\begingroup\$ Why do you need a BMM for this? the memory you mentioned here behave exactly like an SRAM, you only need to provide R/W, CS, OE and address to get the data or write to it. Using the EMC you can choose an SRAM type of memory and you just define the depth and width of your memory, then connect those signals on your top level to the proper signals on the memory. \$\endgroup\$
    – FarhadA
    Commented Mar 28, 2014 at 15:18
  • \$\begingroup\$ Have you been able to get the PSRAM working? \$\endgroup\$ Commented Jun 2, 2014 at 3:26
  • 1
    \$\begingroup\$ @user3602697, apparently not. \$\endgroup\$
    – rdtsc
    Commented Jun 28, 2016 at 0:16

1 Answer 1


Sometimes manufacturers don't provide all of the details in a datasheet. There are a few things to do if you can't find the info you need.

1) Check the product page for additonal resources
2) Check for app notes or tech notes on the product or product family
3) Search horizontally for similar products on the manufactures site or other manufacturers sites for relevant information

Micron cellular ram is a replacement to SRAM.. The routing should be simmilar to SRAM routing because it runs at the same speeds. Here is a guide for all micron routing information

There is also an HDL file on their product page for interfacing in HDL and they have IBIS files for simulating.


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