2.4 System board Troubleshooting 2 Troubleshooting
Table 2-3 D port status (1/6)
D port
status
Inspection items details
Start Clearing a software reset bit
Enabling address line A20
Initializing special registers and Intel chipset
Initializing the CH0 of a PIT
Initializing flags determining whether BIOS is rewritten
CHECK SUM CHECK CHECK SUM CHECK
Switching to protected mode
Examining the checksum of Boot Block
F000h
Examining the checksum of other data in a flash memory
F001h Initializing a KBC (1) Checking if EC/KBC firmware is to be rewritten
Initializing a KBC
Sending command bytes
Sending scan enable command
Checking F12 key-in Checking F12 key-in
F002h Initializing a security controller
F005h Checking whether BIOS
rewrite is requested
Checking whether BIOS rewrite is requested
F006H Checking BIOS signature Checking BIOS signature
Rewriting BIOS Initializing HW
Initializing GPIO I/O space
Enabling BIOS writing
Serial interrupt control
Disabling BIOS write protection
Enabling SMBus I/O space
Enabling SMBus access
Configuring DRAM
Enabling L1 cache memory
Clearing memory
Disabling cache
F007h
Initializing special registers
F008h Changing ROM BIOS to RAM BIOS
Storing key scan code
Setting up TASK_1ms_TSC
F009h
Displaying message on navipanel (EC/KBC UPDATE,
BIOS UPDATA/DAMAGED)
PORTEGE R100 Maintenance Manual (960-440) 2-21
