Usb Programming - Compaq Evo D500 Technical Reference Manual

Chapter 5 Input/Output Interfaces

5.7.2 USB PROGRAMMING

Programming the USB interface consists of configuration, which typically occurs during POST,
and control, which occurs at runtime.
5.7.2.1 USB Configuration
The USB interface functions as a PCI device (31) within the 82801 component (function 2) and is
configured using PCI Configuration Registers as listed in Table 5-17.
Table 5–17. USB Interface Configuration Registers
PCI
Config.
Addr. Register
00, 01h Vender ID
02, 03h Device ID
04, 05h PCI Command
06, 07h PCI Status
08h Revision ID
09h Programming I/F
0Ah Sub Class Code
0Bh Base Class Code
5.7.2.2 USB Control
The USB is controlled through I/O registers as listed in table 5-18.
Table 5–18. USB Control Registers
I/O Addr. Register
00, 01h Command
02, 03h Status
04, 05h Interupt Enable
06, 07 Frame Number
08, 0B Frame List Base Address
0Ch Start of Frame Modify
10, 11h Port 1 Status/Control
12, 13h Port 2 Status/Control
18h Test Data
5-24 Compaq Deskpro and Evo Personal Computers
Featuring Intel Celeron and Pentium III Processors
Table 5-17.
USB Interface Configuration Registers
Reset
Value
8086h
2444h
0000h
0280h
00h
00h
03h
0Ch
Table 5-18.
USB Control Registers
Fifth Edition – March 2002
PCI
Config.
Addr. Register
0Eh Header Type
20-23h I/O Space Base Address
2C, 2Dh Sub. Vender ID
3Ch Interrupt Line
3Dh Interrupt Pin
60h Serial Bus Release No.
C0, C1h USB Leg. Kybd./Ms. Cntrl.
C4h USB Resume Enable
Default Value
0000h
0000h
0000h
0000h
0000h
40h
0080h
0080h
00h
Reset
Value
00h
1
00h
00h
03h
10h
2000h
00h