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.