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Intel Q965 Express Chipset—Error Messages and Beep Codes
Intel
®
Q965 Express Chipset
DM October 2007
47 Order Number: 315664-002US
5.4 Port 80h 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.
The following tables provide information about the POST codes generated by the BIOS:
• Ta ble 25 lists the Port 80h POST code ranges
• Ta ble 26 lists the Port 80h Progress Code Enumeration
• Ta ble 27 lists the Port 80h POST sequence
Table 24. Lists of error messages and brief description of each
Error Message Explanation
CMOS Battery low The battery may be losing power. Replace the battery soon.
CMOS Checksum Bad
The CMOS checksum is incorrect. CMOS memory may have been corrupted.
Run Setup to reset values.
Memory Size Decreased
Memory size has decreased since the last boot. If no memory was removed,
then memory may be bad.
No Boot device available System did not find a device to boot.
Table 25. Port 80h POST Code Ranges
Range Subsystem
0x00 – 0x0F
Debug codes: Can be used by any PEIM/driver for debug. Blocked on production
builds per DFT rule. Not covered in the EPS.
0x10 – 0x1F Host Processors: 0x1F is unrecoverable CPU error.
0x20 – 0x2F Memory/Chipset: 0x2F is no memory detected or no useful memory detected.
0x30 – 0x3F Recovery: 0x3F indicated recovery failure.
0x40 – 0x4F Reserved for future.
0x50 – 0x5F IO Busses: PCI, USB, ISA, ATA etc. 0x5F is unrecoverable error. Start with PCI.
0x60 – 0x6F Reserved for future (for new busses).
0x70 – 0x7F Output Devices: All output consoles. 0x7F is unrecoverable error.
0x80 – 0x8F Reserved for future (new output console codes).
0x90 – 0x9F Input devices: Keyboard/Mouse. 0x9F is unrecoverable error.
0xA0 – 0xAF Reserved for future (new input console codes).
0xB0 – 0xBF
Boot Devices: Includes Fixed media and removable media. Not that critical since
consoles should be up at this point. 0xBF is unrecoverable error.
0xC0-0xCF Reserved for future.
0xD0-0xDF Boot Device Selection.
0xE0 – 0xFF
0xF0 – 0xFF: 0xFF processor exception. 0xE0- 0xEE: Miscellaneous codes. See
below. 0xEF boot/S3: resume failure.