Intel® Server D50TNP Family Integration and Service Guide
208
E.1 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 9. MRC Progress Codes
Post Code
(Hex)
Upper Nibble
Lower Nibble
Description
8h
4h
2h
1h
8h
4h
2h
1h
B0
1
0
1
1
0
0
0
0
Detect DIMM population
B1
1
0
1
1
0
0
0
1
Set DDR4 frequency
B2
1
0
1
1
0
0
1
0
Gather remaining SPD data
B3
1
0
1
1
0
0
1
1
Program registers on the memory controller level
B4
1
0
1
1
0
1
0
0
Evaluate RAS modes and save rank information
B5
1
0
1
1
0
1
0
1
Program registers on the channel level
B6
1
0
1
1
0
1
1
0
Perform the JEDEC defined initialization sequence
B7
1
0
1
1
0
1
1
1
Train DDR4 ranks
1
0
0
0
0
0
0
0
1
Train DDR4 ranks
2
0
0
0
0
0
0
1
0
Train DDR4 ranks
–
Read DQ/DQS training
3
0
0
0
0
0
0
1
1
Train DDR4 ranks
–
Receive enable training
4
0
0
0
0
0
1
0
0
Train DDR4 ranks
–
Write DQ/DQS training
5
0
0
0
0
0
1
0
1
Train DDR4 ranks
–
DDR channel training done
B8
1
0
1
1
1
0
0
0
Initialize CLTT/OLTT
B9
1
0
1
1
1
0
0
1
Hardware memory test and init
BA
1
0
1
1
1
0
1
0
Execute software memory init
BB
1
0
1
1
1
0
1
1
Program memory map and interleaving
BC
1
0
1
1
1
1
0
0
Program RAS configuration
BE
1
0
1
1
1
1
1
0
Execute BSSA RMT
BF
1
0
1
1
1
1
1
1
MRC is done
Should a major memory initialization error occur, preventing the system from booting with data integrity, a
beep code is generated, the MRC displays a fatal error code on the diagnostic LEDs, and a system halt
command is executed. Fatal MRC error halts do not change the state of the system status LED and they do
not get logged as SEL events.
lists all MRC fatal errors that are displayed to the diagnostic LEDs.