82801DB Datasheet, PDF (404/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

USB UHCI Controllers Registers
11.1.13
INTR_LN—Interrupt Line Register (USB—D29:F0/F1/F2)
Address Offset:
3Ch
Default Value:
00h
Attribute:
Size:
R/W
8 bits
Bit
Description
7:0
Interrupt Line (INT_LN) — R/W. This data is not used by the ICH4. It is to communicate to software
the interrupt line that the interrupt pin is connected to.
11.1.14
INTR_PN—Interrupt Pin Register (USB—D29:F0/F1/F2)
Address Offset:
Default Value:
3Dh
Function 0: 01h
Function 1: 02h
Function 2: 03h
Attribute:
Size:
RO
8 bits
Bit
Description
7:3 Reserved
Interrupt Pin (INT_PN) — RO. The values of 01h, 02h, and 03h in function 0, 1, and 2, respectively,
indicate to software that the corresponding ICH4 UHCI USB controllers drive the INTA#, INTB#, and
INTC# PCI signals.
2:0
Note that this does not determine the mapping to the ICH4 PIRQ inputs. Function 0 will drive PIRQA.
Function 1 will drive PIRQD. Function 2 will drive PIRQC. Function 1 does not use the corresponding
mapping in order to spread the interrupts with AC97, which has historically been mapped to PIRQB.
11.1.15
USB_RELNUM—USB Release Number Register
(USB—D29:F0/F1/F2)
Address Offset:
60h
Default Value:
10h
Attribute:
Size:
RO
8 bits
Bit
Description
USB Release Number — RO.
7:0
10h = Indicates that the USB controller is compliant with the USB specification, Release 1.0.
404
Intel^® 82801DB ICH4 Datasheet