82801DB Datasheet, PDF (421/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

EHCI Controller Registers (D29:F7)
12.1.6
12.1.7
12.1.8
12.1.9
PI—Programming Interface Register (USB EHCI—D29:F7)
Address Offset: 09h
Default Value: 20h
Attribute: RO
Size:
8 bits
Bit
Description
7:0
Programming Interface — RO. A value of 20h indicates that this USB High-speed Host controller
conforms to the EHCI Specification.
SCC—Sub Class Code Register (USB EHCI—D29:F7)
Address Offset: 0Ah
Default Value: 03h
Attribute: RO
Size:
8 bits
Bit
Description
7:0 Sub Class Code — RO. A value of 03h indicates that this is a Universal Serial Bus Host controller.
BCC—Base Class Code Register (USB EHCI—D29:F7)
Address Offset: 0Bh
Default Value: 0Ch
Attribute: RO
Size:
8 bits
Bit
Description
7:0 Base Class Code — RO. A value of 0Ch indicates that this is a Serial Bus controller.
MLT— PCI Master Latency Timer Register
(USB EHCI—D29:F7)
Address Offset: 0Dh
Default Value: 00h
Attribute: RO
Size:
8 bits
Bit
Description
Master Latency Timer Count (MLTC) — RO. Hardwired to 00h. Because the USB EHCI controller is
7:0 internally implemented with arbitration via hub interface (and not PCI), it does not need a master
latency timer.
Intel^® 82801DB ICH4 Datasheet
421