Toshiba Tecra A8 Maintenance Manual page 82

2 Troubleshooting Procedures
[ATI chipset model]
Table 2-4-2 Debug port (Boot mode) error status (1/9)
D port status
Boot block Permission of A20 line and clear of
software reset bit
Prohibition of APIC
Initialization of North Bridge and
South Bridge
Initialization of Super I/O
Initialization of debug port
Dummy read of EC 3rd Bus data
Initialization of only PIT CH0
Setting of printer port (only for models
supporting printer port)
CHECK SUM CHECK
Transition to Protect mode
F000 Boot block checksum (skip when
returned to S3)
Checksum other than boot block (skip
when returned to S3)
F001 EC/KBC rewrite check
F002 Initialization of SC
Key input (skip when returned to S3)
F005 Enables CPU cache
F006
Security check
BIOS rewrite request check
F007 Transits to System BIOS IRT
BIOS rewrite process
2-34 [CONFIDENTIAL]
Inspection items
TECRA A8 /Satellite Pro A120 Maintenance Manual (960-573)
2.4 System Board Troubleshooting
Details
(halts, when error)
If "rewrite" is requested, go to "BIOS rewrite
process"
When error, holts. DPORT=F003H or F004H
When a key pressed ,check the key (skip when
returned to S3)
If Checksum check error occurred on except
Boot Block or rewrite is required by user, go to
"BIOS rewrite process".
Initialization of South Bridge
Configuration of DRAM
Permission of cache (L1 cache only)
Memory clear
Transition to real mode and copy of BIOS to
RAM