Early Post Memory Initialization Mrc Diagnostic Codes; Table 4. Mrc Progress Codes - Intel M20MYP1UR Integration And Service Manual

Intel® Server System M20MYP1UR System Integration and Service Guide

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.
Post Code
(Hex) Nibble
Upper
B0
Lower
Upper
B1
Lower
Upper
B2
Lower
Upper
B3
Lower
Upper
B4
Lower
Upper
B5
Lower
Upper
B6
Lower
Upper
B7
Lower
Upper
B8
Lower
Upper
B9
Lower
Upper
BA
Lower
Upper
BB
Lower
Upper
BC
Lower
Upper
BF
Lower

Table 4. MRC progress codes

8h
(MSB) 4h 2h
1 0 1
0 0 0
1 0 1
0 0 0
1 0 1
0 0 1
1 0 1
0 0 1
1 0 1
0 1 0
1 0 1
0 1 0
1 0 1
0 1 1
1 0 1
0 1 1
1 0 1
1 0 0
1 0 1
1 0 0
1 0 1
1 0 1
1 0 1
1 0 1
1 0 1
1 1 0
1 0 1
1 1 1
1h
(LSB)
1
Detect DIMM population
0
1
Set DDR4 frequency
1
1
Gather remaining Serial Presence Detection (SPD) data
0
1
Program registers on the memory controller level
1
1
Evaluate RAS modes and save rank information
0
1
Program registers on the channel level
1
1
Perform the JEDEC defined initialization sequence
0
1
Train DDR4 ranks
1
1
Initialize closed-loop thermal throttling (CLTT) / open-loop
thermal throttling (OLTT)
0
1
Hardware memory test and initialization
1
1
Execute software memory initialization
0
1
Program memory map and interleaving
1
1
Program RAS configuration
0
1
MRC is done
1
Description
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