Difference between revisions of "Developer Manual/RAM init"

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(Remove link to DDR SPD from DDR2 section, add Micron DDR2 datasheets)
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DDR2 SDRAM
 
DDR2 SDRAM
 
* [http://www.jedec.org/download/search/JESD79-2C.pdf JEDEC DDR2 Standard] (PDF)
 
* [http://www.jedec.org/download/search/JESD79-2C.pdf JEDEC DDR2 Standard] (PDF)
* [http://www.jedec.org/download/search/4_01_02_04R13.PDF JEDEC DDR2 SPD Standard] (PDF)
 
 
* [http://www.simmtester.com/PAGE/news/showpubnews.asp?where=373939&num=139 DDR2 DIMM SPD Definition]
 
* [http://www.simmtester.com/PAGE/news/showpubnews.asp?where=373939&num=139 DDR2 DIMM SPD Definition]
<!-- TODO: Add datasheet links (Micron ones are very good) -->
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* Micron DDR2 Datasheets: [http://download.micron.com/pdf/datasheets/modules/ddr2/HTF16C64_128_256x64AG.pdf 512MB-2GB] [http://download.micron.com/pdf/datasheets/modules/ddr2/HTF16C64_128_256x64A.pdf 512MB-4GB]
  
 
DDR3 SDRAM
 
DDR3 SDRAM

Revision as of 00:02, 19 October 2009

One of the most important tasks of coreboot is to initialize your system RAM.

SDRAM

There are a number of steps you have to perform to properly initialize SDRAM. This depends on the chipset, as well as the DIMMs which are inserted into the mainboard (and their properties, such as CAS latencies, and so on).

Sample northbridge datasheets:

Sample SDRAM datasheets:

DDR

DDR2

DDR3

Resources

SDRAM:

DDR SDRAM:

DDR2 SDRAM

DDR3 SDRAM

Note: Micron lists SPD values for all the memory they produce. This really helps when trying to trouble shoot memory and SPD values. Micron SPD Lookup