On 27.11.2007 17:45, Corey Osgood wrote:
ron minnich wrote:
On Nov 27, 2007 8:24 AM, Corey Osgood corey.osgood@gmail.com wrote:
[SPD_MIN_CYCLE_TIME_AT_CAS_MAX] = 10, /* A guess for the tRAC value */
This looks like it's wrong, a normal DDR400 dimm is 0x50 or so.
[SPD_MODULE_ATTRIBUTES] = 0xff, /* FIXME later when we figure out. */
0x20 for an unbuffered dimm, 0x26 for registered.
So I'm going to ask a favor. I am going from the data sheets and could not find this info. Can you look and tell me? I got lost in the numbers ...
I cheated ;) Here's a micron datasheet for a DDR400 CL3 Dimm: http://download.micron.com/pdf/datasheets/modules/ddr/DDA9C16_32_64x72AG.pdf
And what should be known as the best idiot's guide to SPD out there: http://www.simmtester.com/page/news/showpubnews.asp?num=101
I have the JEDEC datasheet on this, but I have so damn many JEDEC datasheets I simply can't figure out which one it is. The "SPD_ACCEPTABLE_CAS_LATENCIES" also should be 0x50 (5ns).
Can you add these links to the wiki, probably to a page about SPD or RAM?
Regards, Carl-Daniel