Usb Programming - HP Compaq D315 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
Each USB controller functions as a PCI device within the MCP component 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 Class Code
0Ch Cache Line Size
0Dh Latency Timer
0Eh Header Type
NOTE:
[1] For D315 = 01C2h; for D325 = 0067h (Cntlr #1), 0067h (Cntlr #2), or 0068h (Cntlr #3)
[2] USB #1 = 02h
USB #2 = 03h
[3] The BIOS will configure this register for 2/4 operation.
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 Interrupt 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 D315 and hp d325 Personal Computers
Featuring the AMD Athlon XP Processor
Table 5-17.
USB Interface Configuration Registers
Reset
Value
10DEh
[1]
0200h
00B0h
A1h
0C0310h
00h
00
00h
Table 5-18.
USB Control Registers
Second Edition – April 2003
PCI
Config.
Addr. Register
0Fh BIST
10h OHCI Memory Base Addr.
3Ch Interrupt Line
3Dh Interrupt Pin
3Eh Minimum Grant
3Fh Maximum Latency
46h Power Mgmt. Capabilities
4Ch Specific Configuration
50h USB Port Mapping
Default Value
0000h
0000h
0000h
0000h
0000h
40h
0080h
0080h
00h
Reset
Value
00h
0s
00h
01h
03h
01h
FE02h
[2]
[3]