E.4 Post Codes - Teknor Industrial Computers VIPer 821 Technical Reference Manual

E.4 POST CODES
NOTE
EISA POST codes are typically output to port address 300h. ISA
POST codes are output to port address 80h.
POST Codes
POST Name
(hex)
C0 Turn Off Chipset Cache
01 Processor Test 1
02 Processor Test 2
03 Initialize Chips
04 Test Memory Refresh Toggle
05 Blank video,
Initialize keyboard
06 Reserved
07 Test CMOS Interface and
Battery Status
BE Chipset Default Initialization
C1 Memory presence test
C5 Early Shadow
C6 Cache presence test
08 Setup low memory
09 Early Cache Initialization
0A Setup Interrupt
Vector Table
0B Test CMOS RAM Checksum
0C Initialize keyboard
OEM Specific-Cache control
Processor Status (1FLAGS) Verification.
Tests the following processor status flags: Carry, zero, sign, overflow.
The BIOS will set each of these flags, verify they are set, then turn each
flag off and verify it is off.
Read/Write/Verify all CPU registers except SS, SP, and BP with data
pattern FF and 00.
Disable NMI, PIE, AIE, UEI, SQWV.
Disable video, parity checking, DMA.
Reset math coprocessor.
Clear all page registers, CMOS shutdown byte.
Initialize timer 0, 1, and 2, including set EISA timer to a known state.
Initialize DMA controllers 0 and 1.
Initialize interrupt controllers 0 and 1.
Initialize EISA extended registers.
RAM must be periodically refreshed in order to keep the memory from
decaying. This function assures that the memory refresh function is
working properly.
Keyboard controller initialization.
Verifies CMOS is working correctly, detects bad battery.
Program chipset registers with power on BIOS defaults.
OEM Specific-Test to size on-board memory.
OEM Specific-Early Shadow enable for fast boot.
External cache size detection.
Early chip set initialization.
Memory presence test.
OEM chip set routines.
Clear low 64K of memory.
Test first 64K memory.
Cyrix CPU initialization.
Cache initialization.
Initialize first 120 interrupt vectors with SPURIOUS_INT_HDLR and
initialize INT 00h-1Fh according to INT_TBL.
Test CMOS RAM Checksum, if bad, or insert key pressed, load
defaults.
Detect type of keyboard controller (optional).
Set NUM LOCK status.
E-5
BIOS Setup Error Codes
Description