Toshiba libretto U100 Maintenance Manual page 66

2 Troubleshooting Procedures
D port Status
F000H
Check sum check
F001H EC/KBC rewrite check
F002H BIOS rewrite request check
F003H
Rewriting BIOS
F004H
2-22 [CONFIDENTIAL]
Table 2-4 D port status (1/8)
Test item
Permission of A20 line and Clearance of software reset
Prohibition of APIC
Initialization for MCH
Initialization for ICHM
Initialization for Super I/O
Initialization for Debug port
Dummy read of 3
Setting of printer port (model supporting printer)
Initialization of only PIT CH0 (for HOLD_ON)
BIOS rewrite flag initialization
Check sum check
returned)
EC/KBC rewrite check
Transition to BIOS rewriting when required
Transits the process to System BIOS IRT side when S3
returned.
Key input
W
key.
BIOS rewrite request check
When checksum error other than in Boot Block is
detected or key rewriting is requested, go to BIOS rewrite
process
Transits the process to System BIOS IRT.
Initialization for CH.D31
Configuration of DRAM
Permission of cache (only L1 cache)
Memory Clear
Shifts to real mode and copies BIOS on RAM.
-
2.4 System Board Troubleshooting
Message
rd
Bus data
Transition to protected mode
Boot block checksum (Skip when S3 is returned)
(HLT when checksum error occurred)
Checksum Except Boot block (Skip when S3 is
hen a key is pressed, check if it is Tilde key or Tab
libretto U100 Maintenance Manual (960-520)