Developer Manual/RAM init - Revision history

Ruud at 19:32, 1 April 2011

2011-04-01T19:32:01Z

Ruud at 19:31, 1 April 2011

2011-04-01T19:31:36Z

Ruud at 19:29, 1 April 2011

2011-04-01T19:29:30Z

Ruud at 19:29, 1 April 2011

2011-04-01T19:29:06Z

Uwe at 01:08, 19 September 2010

2010-09-19T01:08:47Z

Stuge: Remove link to DDR SPD from DDR2 section, add Micron DDR2 datasheets

2009-10-19T00:02:26Z

Remove link to DDR SPD from DDR2 section, add Micron DDR2 datasheets

Uwe: /* Resources */

2009-10-17T22:16:00Z

‎Resources

Uwe: Created page with '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 d…'

2009-06-24T13:29:31Z

Created page with '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 d…'

New page

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:

* [http://www.intel.com/design/chipsets/memory/spdsd12a.pdf Intel SPD Standard]

* [http://download.micron.com/pdf/datasheets/dram/sdram/512MbSDRAM.pdf Micron 512 MB SDRAM Datasheet] (PDF) -- contains some helpful explanations

DDR SDRAM:

* [http://www.jedec.org/download/search/4_01_02_04R13.PDF JEDEC DDR SPD Standard] (PDF)
* [http://www.simmtester.com/page/news/showpubnews.asp?num=101 Understanding DDR Serial Presence Detect (SPD) Table]
* [http://download.micron.com/pdf/datasheets/modules/ddr/DDA9C16_32_64x72AG.pdf Micron DDR400 Datasheet]

DDR2 SDRAM
* [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]


DDR3 SDRAM

* [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. [http://www.micron.com/support/part_info/spd Micron SPD Lookup]

← Older revision		Revision as of 19:32, 1 April 2011
Line 1:		Line 1:
		+	=== Introduction ===
	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'''.

@@ Line 2: / Line 2: @@
 This initialization depends on the type of RAM in your motherboard. To detect the type of RAM the
-SPD (Serial Presence Detect) must be read for each DIMM. This reading is done using I2C communication using one of the [[I2C]] buses on the motherboard. The exact method of reading depends on the motherboard.
+SPD (Serial Presence Detect) must be read for each DIMM. This reading is done using I2C communication using one of the [[Developer Manual/I2C]] buses on the motherboard. The exact method of reading depends on the motherboard.
 === SDRAM ===

@@ Line 2: / Line 2: @@
 This initialization depends on the type of RAM in your motherboard. To detect the type of RAM the
-SPD (Serial Presence Detect) must be read for each DIMM. This reading is done using I2C communication using one of the [I2C] buses on the motherboard. The exact method of reading depends on the motherboard.
+SPD (Serial Presence Detect) must be read for each DIMM. This reading is done using I2C communication using one of the [[I2C]] buses on the motherboard. The exact method of reading depends on the motherboard.
 === SDRAM ===

@@ Line 1: / Line 1: @@
 One of the most important tasks of coreboot is to '''initialize your system RAM'''.
 === SDRAM ===
@@ Line 10: / Line 13: @@
 * http://support.intel.com/design/chipsets/datashts/290656.htm
 * http://download.intel.com/design/chipsets/datashts/29065602.pdf
 Sample SDRAM datasheets:

@@ Line 1: / Line 1: @@
-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 ===
@@ Line 47: / Line 47: @@
 * [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.  [http://www.micron.com/support/part_info/spd Micron SPD Lookup]
+'''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].

@@ Line 38: / Line 38: @@
 DDR2 SDRAM
 * [http://www.jedec.org/download/search/JESD79-2C.pdf JEDEC DDR2 Standard] (PDF)
 * [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) -->
+* 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

@@ Line 26: / Line 26: @@
 SDRAM:
 <!--* [ JEDEC SDRAM Standard] TODO -->
-* [http://www.intel.com/design/chipsets/memory/spdsd12a.pdf Intel SPD Standard]
+* [http://web.archive.org/web/20050307195215/http://www.intel.com/design/chipsets/memory/spdsd12a.pdf Intel SPD Standard]
 <!--* [ JEDEC SPD Standard] TODO -->
 * [http://download.micron.com/pdf/datasheets/dram/sdram/512MbSDRAM.pdf Micron 512 MB SDRAM Datasheet] (PDF) -- contains some helpful explanations