ML410 Board & 1GB DDR2 DIMM Problem

Hi -

I'm having problems getting a 1GB DDR2-667 DIMM to work with an ML410 board. I'm working with the plb_ddr2 IP core in XPS. The auto- generated memory test works perfectly with the 256MB DIMM that the board came with, but once I insert the new DIMM, the test fails every time. Per the data sheet, I incremented the address bus width and changed the memory size. I've tried setting the parameters to match the data sheet, leaving them at the defaults (for a more conservative settings), and innumerable permutations (this is ~week 3 with this problem). We tested the DIMM in a computer, so we know it's good. I've also tried writing to the memory using the debugger, and any data I write refuses to stick. I've never worked with a non-supplied DIMM on a Xilinx board, so I'm probably doing something dumb. What am I doing wrong?

Any help is appreciated.

Reply to
Wren
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You have the extra address lines specified in the UCF file?

Reply to
Brad Smallridge

Yup. I incremented the bus width in the IP configuration, the mhd file, and added an address in the .UCF file, pointing it to the pin last pin referred to in the ML410 user's guide.

Reply to
Wren

The 1 GB DIMM might be a dual bank one. Which means you basically have two 512 Mo DIMM sharing the same lines except clk, cs_n & odt . Not all controller can handle that ... So either you only 512 Mo of it. Or you buy a 2 Go DIMM to use only 1 Go of it.

Sylvain

Reply to
Sylvain Munaut

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