82801DB Datasheet, PDF (313/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

LPC Interface Bridge Registers (D31:F0)
9.1.36
FUNC_DIS—Function Disable Register (LPC I/F—D31:F0)
Offset Address: F2h
Default Value: 00h
Lockable:
No
Attribute:
Size:
Power Well:
R/W
16 bits
Core
Bit
Description
D29_F7_Disable — R/W. Software sets this bit to disable the USB EHCI controller function. BIOS
must not enable I/O or memory address space decode, interrupt generation, or any other
15 ^{functionality of functions that are to be disabled.}
0 = Enable. USB EHCI controller is enabled
1 = Disable. USB EHCI controller is disabled
14
13:11
10
9
8
7
6
5
4
LPC Bridge Disable (D31F0D) — R/W.
0 = Enable.
1 = Disable LPC bridge. When disabled, the following spaces will no longer be decoded by the LPC
bridge:
– Device 31, Function 0 Configuration space
– Memory cycles below 16 MB (100000h)
– I/O cycles below 64 KB (100h)
– The Internal I/OxAPIC at FEC0_0000 to FECF_FFFF
Memory cycles in the LPC BIOS range below 4GB will still be decoded when this bit is set, but
the aliases at the top of 1 MB (the E and F segment) no longer will be decoded.
Reserved
D29_F2_Disable — R/W. Software sets this bit to disable the USB UHCI controller #3 function.
BIOS must not enable I/O or memory address space decode, interrupt generation, or any other
functionality of functions that are to be disabled.
0 = Enable. USB UHCI controller #3 is enabled
1 = Disable. USB UHCI controller #3 is disabled
D29_F1_Disable — R/W. Software sets this bit to disable the USB UHCI controller #2 function.
BIOS must not enable I/O or memory address space decode, interrupt generation, or any other
functionality of functions that are to be disabled.
0 = Enable. USB UHCI controller #2 is enabled
1 = Disable. USB UHCI controller #2 is disabled
D29_F0_Disable — R/W. Software sets this bit to disable the USB UHCI controller #1
function.BIOS must not enable I/O or memory address space decode, interrupt generation, or any
other functionality of functions that are to be disabled.
0 = Enable. USB UHCI controller #1 is enabled
1 = Disable. USB UHCI controller #1 is disabled
Reserved
D31_F6_Disable — R/W. Software sets this bit to disable the AC ’97 modem controller function.
BIOS must not enable I/O or memory address space decode, interrupt generation, or any other
functionality of functions that are to be disabled.
0 = Enable. AC ’97 Modem is enabled
1 = Disable. AC ’97 Modem is disabled
D31_F5_Disable — R/W. Software sets this bit to disable the AC ’97 audio controller function. BIOS
must not enable I/O or memory address space decode, interrupt generation, or any other
functionality of functions that are to be disabled.
0 = Enable. AC ’97 audio controller is enabled
1 = Disable. AC ’97 audio controller is disabled
Reserved
Intel^® 82801DB ICH4 Datasheet
313