Toshiba Portege R200 Maintenance Manual page 61

2.4 System board Troubleshooting
D port Status Test item
F000H
Check sum check
F001H EC/KBC rewrite check
F002H Security initialization
F005H Enabling CPU cache
F006H
BIOS rewrite request check
F007H
Rewriting BIOS
F009H
PORTEGE R200 Maintenance Manual (960-519)
Table 2-4 D port status (1/8)
Message
Permission of A20 line and Clearance of software reset
Prohibition of APIC
Initialization for MCH
Initialization for ICH
Initialization for Super I/O
Initialization for Debug port
Dummy read of 3
Setting of printer port (printer supporting model)
Initialization of only PIT CH0 (for HOLD_ON)
BIOS rewrite flag initialization
Check sum check
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
returned)
EC/KBC rewrite check
Transition to BIOS rewriting when required
Security initialization
(HLT at DPORT=F003H or F004H, when checksum error
occurred)
Key input (Skip when S3 is returned)
Check of Tilde key , Tab key (Skip when S3 is returned)
Enabling CPU cache
BIOS data check
BIOS rewrite request check
When 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.
Stores key scan code.
Setting of TASK_1ms_TSC
2 Troubleshooting
rd
Bus data
[CONFIDENTIAL] 2-21