Compaq 4000N - Manual (Page 128)

Chapter 5 Input/Output Interfaces
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition – September 1997
5-38
5.8.2 USB CONTROL
The USB is controlled through I/O registers as listed in table 5-21.
Table 5–21. USB Control Registers
Table 5-21.
USB Control Registers
I/O Addr. Register
00, 01h Command
02, 03h Status
04, 05h Interupt Enable
06, 07 Frame No.
08, 0B Frame List Base Address
0Ch Start of Frame Modify
10, 11h Port 1 Status/Control
12, 13h Port 2 Status/Control
5.8.3 USB CONNECTOR
The USB interface provides two connectors.
Figure 5–11. Universal Serial Bus Connector (one of two as viewed from rear of chassis)
Table 5–22. USB Connector Pinout
Table 5-22.
USB Connector Pinout
Pin Signal Description Pin Signal Description
1 Vcc +5 VDC 3 USB+ Data (plus)
2 USB- Data (minus) 4 GND Ground
1 2 3 4