Lenovo ThinkPad 600E Technical Reference Manual for the ThinkPad 600 - Page 52
System Control Port B (Hex 0061), IBM Personal, System/2 and Personal Computer BIOS, Interface
View all Lenovo ThinkPad 600E manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 52 highlights
2. Reset the system microprocessor by writing a 1 to bit 0. 3. Issue a Halt instruction to the system microprocessor. 4. Reenable all maskable and nonmaskable interrupts. If you do not follow this procedure, the results are unpredictable. Note: Whenever possible, use BIOS as an interface to reset the system microprocessor to the real mode. For more information about resetting the system microprocessor, refer to the IBM Personal System/2 and Personal Computer BIOS Interface. System Control Port B (Hex 0061) Bit definitions for the write and read functions of this port are shown in the following figures: Bit Function 7-4 Reserved 3 Enable channel check 2 Enable PCI SERR# 1 Enable speaker data 0 Timer 2 gate to speaker Figure 2-32. System Control Port B (Hex 0061, Write) Bit Function 7 PCI SERR# (PCI error) status 6 Channel check status 5 Timer 2 output 4 Toggles with each refresh request 3 Enable channel check 2 Enable PCI SERR# (PCI error) check 1 Enable speaker data 0 Timer 2 gate to speaker Figure 2-33. System Control Port B (Hex 0061, Read) Bit 7 If a system board error occurs and the PCI SERR# line is activated, this bit is set to 1. 2-30 System Board