82801DB Datasheet, PDF (45/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

Signal Description
2.9
USB Interface
Table 2-9. USB Interface Signals
Name
USBP0P,
USBP0N,
USBP1P,
USBP1N
USBP2P,
USBP2N,
USBP3P,
USBP3N
USBP4P,
USBP4N,
USBP5P,
USBP5N
OC[5:0]#
USBRBIAS
USBRBIAS#
Type
I/O
I/O
I/O
I
O
I
Description
Universal Serial Bus Port 1:0 Differential: These differential pairs are used to
transmit data/address/command signals for ports 0 and 1. These ports can be
routed to USB UHCI controller #1 or the USB EHCI controller.
NOTE: No external resistors are required on these signals. The Intel^® ICH4
integrates 15 kΩ pull-downs and provides an output driver impedance
of 45 Ω which requires no external series resistor
Universal Serial Bus Port 3:2 Differential: These differential pairs are used to
transmit data/address/command signals for ports 2 and 3. These ports can be
routed to USB UHCI controller #2 or the USB EHCI controller.
NOTE: No external resistors are required on these signals. The ICH4
integrates 15 kΩ pull-downs and provides an output driver impedance
of 45 Ω which requires no external series resistor
Universal Serial Bus Port 5:4 Differential: These differential pairs are used to
transmit data/address/command signals for ports 4 and 5. These ports can be
routed to USB UHCI controller #3 or the USB EHCI controller.
NOTE: No external resistors are required on these signals. The ICH4
integrates 15 kΩ pull-downs and provides an output driver impedance
of 45 Ω which requires no external series resistor
Overcurrent Indicators: These signals set corresponding bits in the USB
controllers to indicate that an overcurrent condition has occurred.
USB Resistor Bias: Analog connection point for an external resistor to ground.
USBRBIAS should be connected to USBRBIAS# as close to the resistor as
possible.
USB Resistor Bias Complement: Analog connection point for an external
resistor to ground. USBRBIAS# should be connected to USBRBIAS as close to
the resistor as possible.
Intel^® 82801DB ICH4 Datasheet
45