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Appendix B: LED Decoder
98
Intel
®
Compute Module MFS2600KI User Guide
Table 9. MRC Progress Codes
Checkpoint
Diagnostic LED Decoder
Description
1 = LED On, 0 = LED Off
Upper Nibble
Lower Nibble
MSB
LSB
8h
4h
2h
1h
8h
4h
2h
1h
LED
#
7
#
6
#
5
#
4
#
3
#
2
#
1
#
0
MRC Progress Codes
B0h
1
0
1
1
0
0
0
0
Detect DIMM population
B1h
1
0
1
1
0
0
0
1
Set DDR3 frequency
B2h
1
0
1
1
0
0
1
0
Gather remaining SPD data
B3h
1
0
1
1
0
0
1
1
Program registers on the memory controller level
B4h
1
0
1
1
0
1
0
0
Evaluate RAS modes and save rank information
B5h
1
0
1
1
0
1
0
1
Program registers on the channel level
B6h
1
0
1
1
0
1
1
0
Perform the JEDEC defined initialization sequence
B7h
1
0
1
1
0
1
1
1
Train DDR3 ranks
B8h
1
0
1
1
1
0
0
0
Initialize CLTT/OLTT
B9h
1
0
1
1
1
0
0
1
Hardware memory test and init
BAh
1
0
1
1
1
0
1
0
Execute software memory init
BBh
1
0
1
1
1
0
1
1
Program memory map and interleaving
BCh
1
0
1
1
1
1
0
0
Program RAS configuration
BFh
1
0
1
1
1
1
1
1
MRC is done
Memory Initialization at the beginning of POST includes multiple functions, including: 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.
When a major memory initialization error occurs and prevents the system from booting with data
integrity, a beep code is generated, the MRC will display 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. The following table lists all MRC
fatal errors that are displayed to the Diagnostic LEDs.
Table 10. MRC Fatal Error Codes
Checkpoint
Diagnostic LED Decoder
Description
1 = LED On, 0 = LED Off
Upper Nibble
Lower Nibble
MSB
LSB
8h
4h
2h
1h
8h
4h
2h
1h
LED
#
7
#
6
#
5
#
4
#
3
#
2
#
1
#
0
MRC Fatal Error Codes
E8h
1
1
1
0
1
0
0
0
No usable memory error
E9h
1
1
1
0
1
0
0
1
Memory is locked by Intel
®
Trusted Execuiton
Technology and is inaccessible
EAh
1
1
1
0
1
0
1
0
DDR3 channel training error
EBh
1
1
1
0
1
0
1
1
Memory test failure