Product specifications

Design Guide - VT82C694X Apollo Pro133 with VT82C686A
Preliminary Revision 0.5, November 19, 1999 Signal Connectivity and Design Checklist
83
Technologies, Inc.
We ConnectWe Connect
USB INTERFACE
Signal Name I/O Connection
USBP0+,
USBP0-
IO Connect to USB(0) connector. 47pF capacitor to ground with 27 ohm resistor, and then
15K ohm resistor to ground. These passive components should be placed as close to
VT82C686A as possible
OC0#/
DACK2#/
GPIOF
I
I
IO
Connect to the corresponding USB(0) over-current detection voltage divider.
USBP1+,
USBP1-
IO Connect to USB(1) connector. 47pF capacitor to ground with 27 ohm resistor, and then
15K ohm resistor to ground. These passive components should be placed as close to
VT82C686A as possible
OC1#/
DRQ2/
GPIOF/
SERIRQ
I
I
IO
I
Connect to the corresponding USB(1) over-current detection voltage divider.
USBP2+,
USBP2-
IO Connect to USB(2) connector. 47pF capacitor to ground with 27 ohm resistor, and then
15K ohm resistor to ground. These passive components should be placed as close to
VT82C686A as possible
USBP3+,
USBP3-
IO Connect to USB(3) connector. 47pF capacitor to ground with 27 ohm resistor, and then
15K ohm resistor to ground. These passive components should be placed as close to
VT82C686A as possible
USBCLK I Connect to a 48MHz clock output of the system clock synthesizer.
SYSTEM MANAGEMENT BUS INTERFACE
Signal Name I/O Connection
SMBCLK,
SMBDATA
IO Connect to all devices on SMBus (I2C bus) except for the VGA port. 2.2K ohm pull-up to
VCC3. This resistor value is varied based on the bus loading.
SMBALRT/GPI6 I 10K ohm pull-up to 3VSB (3.3V stand-by power source).