Appendix D: POST Code Diagnostic LED Decoder
Intel
®
Server Board S5500BC TPS
Intel order number: E42249-003
Revision 1.0
100
Table 45. Diagnostic LED POST Code Decoder
Diagnostic LED Decoder
O = On, X=Off
Upper Nibble
Lower Nibble
MSB
LSB
Checkpoint
8h 4h 2h 1h 8h 4h 2h 1h
LED
#7 #6 #5 #4 #3 #2 #1 #0
Description
Host Processor
0x10h X X X O X X X X Power-on
initialization of the host processor (bootstrap processor)
0x11h X X X O X X X O Host
processor
cache initialization (including AP)
0x12h X X X O X X O X Starting
application processor initialization
0x13h X X X O X X O O SMM
initialization
Chipset
0x21h X X O X X X X O Initializing
a
chipset
component
Memory
0x22h
X
X
O
X
X
X
O
X
Reading configuration data from memory (SPD on DIMM)
0x23h X X O X X X O O Detecting
presence
of
memory
0x24h X X O X
X O X X Programming
timing
parameters in the memory controller
0x25h X X O X X O X O Configuring
memory parameters in the memory controller
0x26h X X O X X O O X Optimizing
memory
controller
settings
0x27h
X
X
O
X
X
O
O
O
Initializing memory, such as ECC init
0x28h X X O X O X X X Testing
memory
PCI Bus
0x50h X O X O X X X X Enumerating PCI buses
0x51h X O X O X X X O Allocating
resources
to
PCI
buses
0x52h X O X O X X O X Hot
Plug
PCI
controller
initialization
0x53h X O X O X X O O Reserved
for
PCI
bus
0x54h X O X O X O X X Reserved
for
PCI
bus
0x55h X O X O X O X O Reserved
for
PCI
bus
0X56h X O X O X O O X Reserved
for
PCI
bus
0x57h X O X O X O O O Reserved
for
PCI
bus
USB
0x58h X O X O O X X X Resetting
USB
bus
0x59h X O X O O X X O Reserved
for
USB
devices
ATA/ATAPI/SATA
0x5Ah
X
O
X
O
O
X
O
X
Resetting SATA bus and all devices
0x5Bh X O X O O X O O Reserved
for
ATA
SMBUS
0x5Ch X O X O O O X X Resetting
SMBUS
0x5Dh X O X O O O X O Reserved
for
SMBUS
Local Console
0x70h
X
O
O
O
X
X
X
X
Resetting the video controller (VGA)
0x71h
X
O
O
O
X
X
X
O
Disabling the video controller (VGA)
0x72h
X
O
O
O
X
X
O
X
Enabling the video controller (VGA)
Remote Console
0x78h
X
O
O
O
O
X
X
X
Resetting the console controller
0x79h X O O O O X X O Disabling
the
console
controller
0x7Ah X O O O O X O X Enabling
the
console
controller
Keyboard (only USB)
0x90h O X X O X X X X Resetting
the
keyboard
0x91h O X X O X X X O Disabling
the
keyboard
0x92h O X X O X X O X Detecting
the presence of the keyboard
0x93h O X X O X X O O Enabling
the
keyboard
0x94h O X X O X O X X Clearing
keyboard
input
buffer
0x95h O X X O X O X O Instructing
keyboard
controller to run Self Test(PS/2 only)
Mouse (only USB)
0x98h O X X O O X X X Resetting
the
mouse
