82801BA Datasheet, PDF (223/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

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 ICH2 positively decodes the cycle. If the
response is on the behalf of an LPC device, ICH2 will forward the cycle to the LPC interface.
Refer to Table A-2 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 ICH2 does not perform any
checks for conflicts.
Table 6-3. Variable I/O Decode Ranges
Range Name
ACPI
IDE
USB #1
SMBus
AC’97 Audio Mixer
AC’97 Bus Master
AC’97 Modem Mixer
TCO
GPIO
Parallel Port
Serial Port 1
Serial Port 2
Floppy Disk Controller
MIDI
MSS
SoundBlaster
LAN
USB #2
LPC Generic 1
LPC Generic 2
Mappable
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
96 Bytes above ACPI Base
Anywhere in 64 KB I/O Space
3 ranges in 64 KB I/O Space
8 Ranges in 64 KB I/O Space
8 Ranges in 64 KB I/O Space
2 Ranges in 64 KB I/O Space
4 Ranges in 64 KB I/O Space
4 Ranges in 64 KB I/O Space
2 Ranges in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Anywhere in 64 KB I/O Space
Monitors 4:7
Anywhere in 64 KB I/O Space
Size (Bytes)
64
16
32
16
256
64
256
32
64
8
8
8
8
2
8
32
64
32
128
16
16
Target
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
LPC Peripheral
LPC Peripheral
LPC Peripheral
LPC Peripheral
LPC Peripheral
LAN Unit
USB Unit 2
LPC Peripheral
LPC Peripheral
LPC Peripheral or Trap on
PCI
82801BA ICH2 and 82801BAM ICH2-M Datasheet
6-5