82801DB Datasheet, PDF (572/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

Register Index
Table A-2. Intel^® ICH4 Fixed I/O Registers (Sheet 2 of 2)
Register Name
Operational Control Word 3
Registerr
Master Controller Edge/Level
Triggered Register
Slave Controller Edge/Level
Triggered Register
NMI Status and Control Register
NMI Enable Register
PORT92 – Fast A20 and Init
Register
Coprocessor Error Register
Reset Control Register
Advanced Power Management
Control Port Register
Advanced Power Management
Status Port Register
PIO Mode Command Block Offset
for Secondary Drive
PIO Mode Command Block Offset
for Primary Drive
PIO Mode Control Block Offset for
Secondary Drive
PIO Mode Control Block Offset for
Primary Drive
Port
Datasheet Location
20h
4D0h
4D1h
Section 9.4.8, “OCW3—Operational Control Word 3 Register” on
page 9-328
Section 9.4.9, “ELCR1—Master Controller Edge/Level Triggered Register”
on page 9-329
Section 9.4.10, “ELCR2—Slave Controller Edge/Level Triggered Register”
on page 9-330
Processor Interface Registers
61h
Section 9.7.1, “NMI_SC—NMI Status and Control Register” on page 9-342
70h
Section 9.7.2, “NMI_EN—NMI Enable (and Real Time Clock Index)
Register” on page 9-343
92h
Section 9.7.3, “PORT92—Fast A20 and Init Register” on page 9-343
F0h
CF9h
Section 9.7.4, “COPROC_ERR—Coprocessor Error Register” on
page 9-343
Section 9.7.5, “RST_CNT—Reset Control Register” on page 9-344
APM I/O Decode Registers
B2h
Section 9.8.2.1, “APM_CNT—Advanced Power Management Control Port
Register” on page 9-352
B3h
Section 9.8.2.2, “APM_STS—Advanced Power Management Status Port
Register” on page 9-352
PIO Mode Registers
170h–177h See ATA Specification for detailed register description
1F0h–1F7h See ATA Specification for detailed register description
376h
See ATA Specification for detailed register description
3F6h
See ATA Specification for detailed register description
NOTE: When the POS_DEC_EN bit is set, additional I/O ports get positively decoded by the ICH4. Refer to
through for a listing of these ranges.
572
Intel^® 82801DB ICH4 Datasheet