Appendix E: POST Code Diagnostic LED Decoder  Intel
®
 Server Board S2600CP and Server System P4000CP TPS 
  Revision 1.1 
Intel order number G26942-003 
194
In the following example, the BIOS sends a value of ACh to the diagnostic LED decoder. The 
LEDs are decoded as follows: 
Table 151. POST Progress Code LED Example 
LEDs 
Upper Nibble AMBER LEDs Lower Nibble GREEN LEDs 
MSB              LSB 
LED #7  LED #6  LED #5
LED #4
LED #3
LED #2
LED #1  LED #0
8h  4h  2h  1h  8h  4h  2h  1h 
Status  ON  OFF  ON  OFF  ON  ON  OFF  OFF 
Results 
1 0 1 0 1 1 0 0 
Ah Ch 
Upper nibble bits = 1010b = Ah; Lower nibble bits = 1100b = Ch; the two are concatenated as 
ACh 
 
The following table provides a list of all POST progress codes. 
Table 152. POST 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
SEC Phase 
01h  0  0  0  0  0  0  0  1 First POST code after CPU reset 
02h  0  0  0  0  0  0  1  0 Microcode load begin 
03h  0  0  0  0  0  0  1  1 CRAM initialization begin 
04h  0  0  0  0  0  1  0  0 Pei Cache When Disabled 
05h  0  0  0  0  0  1  0  1 SEC Core At Power On Begin. 
06h  0  0  0  0  0  1  1  0 Early CPU initialization during Sec Phase. 
07h  0  0  0  0  0  1  1  1 Early SB initialization during Sec Phase. 
08h  0  0  0  0  1  0  0  0 Early NB initialization during Sec Phase. 
09h  0  0  0  0  1  0  0  1 End Of Sec Phase. 
0Eh  0  0  0  0  1  1  1  0 Microcode Not Found. 
0Fh  0  0  0  0  1  1  1  1 Microcode Not Loaded. 
PEI Phase 
10h  0  0  0  1  0  0  0  0 PEI Core 
11h  0  0  0  1  0  0  0  1 CPU PEIM 
15h  0  0  0  1  0  1  0  1 NB PEIM 
19h  0  0  0  1  1  0  0  1 SB PEIM 
MRC Process Codes – MRC Progress Code Sequence is executed  - See Table 63 
PEI Phase continued… 
31h  0  0  1  1  0  0  0  1 Memory Installed 
32h  0  0  1  1  0  0  1  0 CPU PEIM (Cpu Init) 
33h  0  0  1  1  0  0  1  1 CPU PEIM (Cache Init) 
34h  0  0  1  1  0  1  0  0 CPU PEIM (BSP Select) 
35h  0  0  1  1  0  1  0  1 CPU PEIM (AP Init) 
36h  0  0  1  1  0  1  1  0 CPU PEIM (CPU SMM Init) 
4Fh  0  1  0  0  1  1  1  1 Dxe IPL started 
DXE Phase 
60h  0  1  1  0  0  0  0  0 DXE Core started 
61h  0  1  1  0  0  0  0  1 DXE NVRAM Init 
62h  0  1  1  0  0  0  1  0 SB RUN Init 
63h  0  1  1  0  0  0  1  1 Dxe CPU Init