Toshiba Tecra M2-S519 Maintenance Manual - Page 74

2 Troubleshooting Procedures 2.4 System Board Troubleshooting Table 2-5 Printer port LED boot mode status (1/7) LED Status Start Test item B0h Flash ROM check B1h EC/KBC rewrite check B2h Start initializing the SC Executing initialization of KBC sequence B5h Enabling CPU cache B6h BIOS signature check BIOS rewrite request check B7h System BIOS rewrite transition to IRT Rewriting BIOS H/W initialization Initialization of PIT channel 1 (Setting refresh interval to 30ms) Initialization of PIT, DMAC, PIC Prohibition of cache Message Clearance of software reset bit Permission of A20 line Initialization for special register and Intel chip set PIT CH0 initialization (for HOLD_ON) BIOS rewrite flag initialization Checksum check (FEF00000h-FEFF7FFFh) Transition to protected mode Boot block checksum (HLT when checksum error occurred.) Checksum check except boot block Transition to BIOS rewriting when required (HLT when Initialization for SC error occurred) B3H (HLT when processing the SC can not be continued by the HW failure) B4H transmission of KB enable command Key check at Boot Block Checksum error except boot block (When key rewriting is requested, go to BIOS rewrite process) Setting of base for Power Management I/O Space Permission of BIOS writing Serial interrupt control Releasing BIOS rewrite protection Enabling SM Bus I/O space Enabling SM Bus access Opening work I/O for SDRAM initialization Setting FDC port 2-20 TECRA M2 Maintenance Manual (960-468)