Toshiba TECRA M9 Maintenance Manual page 70

2 Troubleshooting Procedures
Table 2-5 Serial port (Boot mode) error status (1/9)
D port
Status
Boot Block Permission of A20 and clear of software
reset bit
Prohibition of APIC
Initialization of MCH, ICH
Initialization of Super I/O
Initialization of debug port (For models
supporting debug port)
Dummy read of 3
Setting of printer port (For models
supporting printer port)
F0B0h PIT CH0 initialization (for HOLD_ON)
BIOS rewrite factor flag initialization
CHECK SUM CHECK
F0B1h EC/KBC rewrite check
Key input
F0B2h Initialization of SC
F0B6h BIOS rewrite request check
F0B7h Transits to System BIOS IRT
BIOS rewrite process
Initialization of ICH. D31
DRAM configuration
Permission of cache (L1 cache only)
Memory clear
Transition to real mode and copy of BIOS
to RAM
2-20
Test item
rd
Bus data
[CONFIDENTIAL]
2.4 System Board Troubleshooting
Contents
Transition to protected mode
Boot block checksum (skipped when
returned from S3)
Halts when error occurs
Checksum other than boot block (skipped
when returned from S3)
If "rewrite" is requested, go to "BIOS rewrite
process"
Transition to system BIOS IRT（when
returned to S3)
". When a key is pressed, check if it is Tilde
key or Tab key. (skipped when returned from
S3)
HLT at LED=B3H or B4, when error occurs
If Checksum check error occurred on except
Boot Block or rewrite is required by user, go
to "BIOS rewrite process".
TECRA M9 Maintenance Manual (960-631)