82801DB Datasheet, PDF (248/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

Register and Memory Mapping
6.3.2 Variable I/O Decode Ranges
Table 6-3 shows the Variable I/O Decode Ranges. They are set using Base Address Registers
(BARs) or other configuration bits in the various PCI configuration spaces. The PNP software (PCI
or ACPI) can use their configuration mechanisms to set and adjust these values.
When a cycle is detected on the hub interface, the ICH4 will positively decode the cycle. If the
response is on the behalf of an LPC device, ICH4 will forward the cycle to the LPC I/F.
Refer to Table A-3 for a complete list of all variable I/O registers.
Warning: The Variable I/O Ranges should not be set to conflict with the Fixed I/O Ranges. Unpredictable
results if the configuration software allows conflicts to occur. The ICH4 does not perform any
checks for conflicts.
Table 6-3. Variable I/O Decode Ranges
Range Name
Mappable
Size (Bytes)
Target
ACPI
Anywhere in 64-KB I/O Space
64
IDE Bus Master
Anywhere in 64-KB I/O Space
16
USB UHCI Controller #1 Anywhere in 64-KB I/O Space
32
SMBus
Anywhere in 64-KB I/O Space
32
AC ’97 Audio Mixer
Anywhere in 64-KB I/O Space
256
AC ’97 Bus Master
Anywhere in 64-KB I/O Space
64
AC ’97 Modem Mixer
Anywhere in 64-KB I/O Space
256
TCO
96 Bytes above ACPI Base
32
GPIO
Anywhere in 64-KB I/O Space
64
Parallel Port
3 ranges in 64-KB I/O Space
8
Serial Port 1
8 Ranges in 64-KB I/O Space
8
Power Management
IDE Unit
USB Unit 1
SMB Unit
AC ’97 Unit
AC ’97 Unit
AC ’97 Unit
TCO Unit
GPIO Unit
LPC Peripheral
LPC Peripheral
Serial Port 2
8 Ranges in 64-KB I/O Space
8
Floppy Disk Controller
2 Ranges in 64-KB I/O Space
8
MIDI
4 Ranges in 64-KB I/O Space
2
LPC Peripheral
LPC Peripheral
LPC Peripheral
MSS
SoundBlaster
LAN
4 Ranges in 64-KB I/O Space
8
2 Ranges in 64-KB I/O Space
32
Anywhere in 64-KB I/O Space
64
LPC Peripheral
LPC Peripheral
LAN Unit
USB UHCI Controller #2 Anywhere in 64-KB I/O Space
32
USB UHCI Controller #3 Anywhere in 64-KB I/O Space
32
LPC Generic 1
Anywhere in 64-KB I/O Space
128
USB Unit 2
USB Unit 3
LPC Peripheral
LPC Generic 2
Anywhere in 64-KB I/O Space
16
LPC Peripheral
Monitors 4:7
Anywhere in 64-KB I/O Space
16
LPC Peripheral or Trap on PCI
Native IDE Primary
Command
Anywhere in 64-KB I/O Space
8
IDE Unit
Native IDE Primary Control Anywhere in 64-KB I/O Space
4
IDE Unit
Native IDE Secondary
Command
Anywhere in 64-KB I/O Space
8
IDE Unit
Native IDE Secondary
Control
Anywhere in 64-KB I/O Space
4
IDE Unit
248
Intel^® 82801DB ICH4 Datasheet