82801DB Datasheet, PDF (400/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

USB UHCI Controllers Registers
11.1.2
11.1.3
DID—Device Identification Register (USB—D29:F0/F1/F2)
Address Offset:
Default Value:
02–03h
Function 0: 24C2h
Function 1: 24C4h
Function 2: 24C7h
Attribute:
Size:
RO
16 bits
Bit
Description
15:0
Device Identification Value — RO. This is a 16-bit value assigned to the ICH4 USB Host
controllers.
CMD—Command Register (USB—D29:F0/F1/F2)
Address Offset:
Default Value:
04–05h
0000h
Attribute:
Size:
R/W, RO
16 bits
Bit
15:10
9
8
7
6
5
4
3
2
1
0
Description
Reserved
Fast Back to Back Enable (FBE) — RO. Reserved as 0.
SERR# Enable (SERR_EN) — RO. Reserved as 0.
Wait Cycle Control (WCC) — RO. Reserved as 0.
Parity Error Response (PER) — RO. Reserved as 0.
VGA Palette Snoop (VSP) — RO. Reserved as 0.
Postable Memory Write Enable (PMWE) — RO. Reserved as 0.
Special Cycle Enable (SCE) — RO. Reserved as 0.
Bus Master Enable (BME) — RW. When set, the ICH4 can act as a master on the PCI bus for USB
transfers.
Memory Space Enable (MSE) — RO. Reserved as 0.
I/O Space Enable (IOSE) — RW. This bit controls access to the I/O space registers.
0 = Disable
1 = Enable accesses to the USB I/O registers. The Base Address register for USB should be
programmed before this bit is set.
400
Intel^® 82801DB ICH4 Datasheet