Intel M20MYP1UR, Integration And Service Manual

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Intel® Server System M20MYP1UR System Integration and Service Guide
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Early POST Memory Initialization MRC Diagnostic Codes
Memory initialization at the beginning of POST includes multiple functions: discovery, channel training,
validation that the DIMM population is acceptable and functional, initialization of the IMC and other
hardware settings, and initialization of applicable RAS configurations.
The MRC progress codes are displayed to the diagnostic LEDs that show the execution point in the MRC
operational path at each step.
Table 4. MRC progress codes
Post Code
(Hex) Nibble
8h
(MSB) 4h 2h
1h
(LSB) Description
B0
Upper 1 0 1 1
Detect DIMM population
Lower 0 0 0 0
B1
Upper 1 0 1 1
Set DDR4 frequency
Lower 0 0 0 1
B2
Upper 1 0 1 1
Gather remaining Serial Presence Detection (SPD) data
Lower 0 0 1 0
B3
Upper 1 0 1 1
Program registers on the memory controller level
Lower 0 0 1 1
B4
Upper 1 0 1 1
Evaluate RAS modes and save rank information
Lower 0 1 0 0
B5
Upper 1 0 1 1
Program registers on the channel level
Lower 0 1 0 1
B6
Upper 1 0 1 1
Perform the JEDEC defined initialization sequence
Lower 0 1 1 0
B7
Upper 1 0 1 1
Train DDR4 ranks
Lower 0 1 1 1
B8
Upper 1 0 1 1
Initialize closed-loop thermal throttling (CLTT) / open-loop
thermal throttling (OLTT)
Lower 1 0 0 0
B9
Upper 1 0 1 1
Hardware memory test and initialization
Lower 1 0 0 1
BA
Upper 1 0 1 1
Execute software memory initialization
Lower 1 0 1 0
BB
Upper 1 0 1 1
Program memory map and interleaving
Lower 1 0 1 1
BC
Upper 1 0 1 1
Program RAS configuration
Lower 1 1 0 0
BF
Upper 1 0 1 1
MRC is done
Lower 1 1 1 1