Developer Manual/RAM init: Difference between revisions
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(Remove link to DDR SPD from DDR2 section, add Micron DDR2 datasheets) |
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One of the most important tasks of coreboot is to initialize your system RAM. | One of the most important tasks of coreboot is to '''initialize your system RAM'''. | ||
=== SDRAM === | === SDRAM === | ||
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* [http://www.simmtester.com/PAGE/news/showpubnews.asp?num=153 Understanding DDR3 Serial Presence Detect (SPD) Table] | * [http://www.simmtester.com/PAGE/news/showpubnews.asp?num=153 Understanding DDR3 Serial Presence Detect (SPD) Table] | ||
Note: Micron lists SPD values for all the memory they produce. This really helps when trying to trouble shoot memory and SPD values. | '''Note:''' Micron lists SPD values for all the memory they produce. This really helps when trying to trouble shoot memory and SPD values. [http://www.micron.com/support/part_info/spd Micron SPD Lookup]. | ||
Revision as of 01:08, 19 September 2010
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:
- http://support.intel.com/design/chipsets/810/
- http://support.intel.com/design/chipsets/datashts/290656.htm
- http://download.intel.com/design/chipsets/datashts/29065602.pdf
Sample SDRAM datasheets:
- http://www.micron.com/products/partdetail?part=MT48LC16M16A2BG-75
- http://download.micron.com/pdf/datasheets/dram/sdram/256MSDRAM.pdf
DDR
DDR2
DDR3
Resources
SDRAM:
- Intel SPD Standard
- Micron 512 MB SDRAM Datasheet (PDF) -- contains some helpful explanations
DDR SDRAM:
- JEDEC DDR SPD Standard (PDF)
- Understanding DDR Serial Presence Detect (SPD) Table
- Micron DDR400 Datasheet
DDR2 SDRAM
- JEDEC DDR2 Standard (PDF)
- DDR2 DIMM SPD Definition
- Micron DDR2 Datasheets: 512MB-2GB 512MB-4GB
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.