Learning resources for Xilinx memory controllers


I'm working on a design that will require external memory, and I'm trying to find some learning resources for Xilinx DDR SDRAM memory controllers. I don't have much VHDL/FPGA design experience and all the resources I can find assume that you implicitly know how to use a memory controller.

The Xilinx models from their web site just unzip to a whole bunch of vhdl files and their documentation is not user oriented - it's an explanation of how their controller is implemented (I don't care!).

The memory controller performance/specification isn't important to me right now, but without being able to simulate a controller I can't proceed further with my circuit design. I'm using ISE and ModelSim.

Do I need to go down the Denali route and purchase a memory model then lean on their technical support? Or should I just give up and get a consultant to help?


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You may need a simulation model of the DDR SDRAM, this will let you simulate the controller core's interactions with the memory.

Micron.com are pretty good about supplying useful VHDL simulation models for their memory devices.

- Brian

Reply to
Brian Drummond

I agree 100% about those memory controller app notes - while it's important to know how they work internally, they really fall down on how to hook them up internally, and to a lesser extent externally. (my particular experience was the DDR app note for spartan3). We finally ended up giving up on the thing and reused a slower design we had done for v2.

Most of the notes seem somewhat evolutionary from some old reference design where they keep replacing the tricky bits, so if you dig back far enough to one of the really old notes (maybe it was for virtex?) they have some info about what to do with the pieces they give you, but it's really painful.

Reply to
Andrew Dyer

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