Intel DB75EN Technical Product Specification - Page 75

Port 80h Power On Self Test POST Codes

Page 75 highlights

Error Messages and Beep Codes 4.5 Port 80h Power On Self Test (POST) Codes During the POST, the BIOS generates diagnostic progress codes (POST codes) to I/O port 80h. If the POST fails, execution stops and the last POST code generated is left at port 80h. This code is useful for determining the point where an error occurred. Displaying the POST codes on a medium such as a seven-segment display, requires a POST card that can interface with the Low Pin Count (LPC) Debug header or a POST card that can be installed in one of the Conventional PCI connectors. Refer to the location of the LPC Debug header in Figure 1. The following tables provide information about the POST codes generated by the BIOS: • Table 46 lists the Port 80h POST code ranges • Table 47 lists the Port 80h POST codes themselves • Table 48 lists the Port 80h POST sequence NOTE In the tables listed above, all POST codes and range values are listed in hexadecimal. Table 46. Port 80h POST Code Ranges Range Subsystem 0x00 - 0x05 Entering SX states S0 to S5. 0x10, 0x20, 0x30, 0x40, 0x50 0x08 - 0x0F Resuming from SX states. 0x10 - S1, 0x20 - S2, 0x30 - S3, etc. Security (SEC) phase 0x11 - 0x1F PEI phase pre MRC execution 0x21 - 0x29 MRC Memory detection 0x2A - 0x2F PEI phase post MRC execution 0x31 - 0x35 Recovery 0x36 - 0x3F Platform DXE driver 0x41 - 0x4F CPU Initialization (PEI, DXE, SMM) 0x50 - 0x5F I/O Buses: PCI, USB, ISA, ATA etc. 0x5F is an unrecoverable error. Start with PCI. 0x60 - 0x6F 0x70 - 0x7F 0x80 - 0x8F 0x90 - 0x9F 0xA0 - 0xAF 0xB0 - 0xBF BDS Output Devices: All output consoles. For future use Input devices: Keyboard/Mouse. For future use Boot Devices: Includes fixed media and removable media. Not that critical since consoles should be up at this point. 0xC0 - 0xCF For future use 0xD0 - 0xDF For future use 0xF0 - 0xFF 75

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Error Messages and Beep Codes
75
4.5
Port 80h Power On Self Test (POST) Codes
During the POST, the BIOS generates diagnostic progress codes (POST codes) to I/O
port 80h.
If the POST fails, execution stops and the last POST code generated is left
at port 80h.
This code is useful for determining the point where an error occurred.
Displaying the POST codes on a medium such as a seven-segment display, requires a
POST card that can interface with the Low Pin Count (LPC) Debug header or a POST
card that can be installed in one of the Conventional PCI connectors.
Refer to the
location of the LPC Debug header in Figure 1.
The following tables provide information about the POST codes generated by the BIOS:
Table 46 lists the Port 80h POST code ranges
Table 47 lists the Port 80h POST codes themselves
Table 48 lists the Port 80h POST sequence
NOTE
In the tables listed above, all POST codes and range values are listed in hexadecimal.
Table 46.
Port 80h POST Code Ranges
Range
Subsystem
0x00 – 0x05
Entering SX states S0 to S5.
0x10, 0x20, 0x30,
0x40, 0x50
Resuming from SX states. 0x10 – S1, 0x20 – S2, 0x30 – S3, etc.
0x08 – 0x0F
Security (SEC) phase
0x11 – 0x1F
PEI phase pre MRC execution
0x21 – 0x29
MRC Memory detection
0x2A – 0x2F
PEI phase post MRC execution
0x31 – 0x35
Recovery
0x36 – 0x3F
Platform DXE driver
0x41 – 0x4F
CPU Initialization (PEI, DXE, SMM)
0x50 – 0x5F
I/O Buses:
PCI, USB, ISA, ATA etc. 0x5F is an unrecoverable error. Start with PCI.
0x60 – 0x6F
BDS
0x70 – 0x7F
Output Devices:
All output consoles.
0x80 – 0x8F
For future use
0x90 – 0x9F
Input devices:
Keyboard/Mouse.
0xA0 – 0xAF
For future use
0xB0 – 0xBF
Boot Devices:
Includes fixed media and removable media. Not that critical since
consoles should be up at this point.
0xC0 – 0xCF
For future use
0xD0 – 0xDF
For future use
0xF0 – 0xFF