*Notice: The information in this document is subject to change without notice
5-36
Notes
Chapter 5 Configuration Registers
To select many of the many options available on the HyperTransport PCI bridge, you write to its configura-
tion registers. Usually, these registers are programmed during system initialization and are not accessed
during normal operation.
This section describes the mechanism used to access the HyperTransport PCI bridge configuration regis-
ters as well as the location and functional details of each register.
Configuration Mechanism
Configuration accesses are accepted from HyperTransport to the HyperTransport PCI bridge internal
CSRs if they are Type 0 accesses with a device number equal to the value in the BaseUnitId field of the
HyperTransport Command CSR.
5.1 Summary of Configuration Registers
Table 5.1 summarizes the HyperTransport PCI bridge configuration register offsets, devices, default values
after reset, and access types.
5.1.1 Register Access Definitions
Access types are indicated as follows:
•
R – ReadA read of this register returns the field.
•
W – WriteA write of this register loads the value.
•
T – ToggleA write of 1 to this field toggles the value.
•
S – SetA write of 1 to this field sets the field.
•
C – ClearA write of 1 to this field clears the field.
5.1.2 Register Access Rules
Several rules apply to HyperTransport PCI bridge CSR accesses.
•
Reads to undefined fields return undefined data.
•
Writes to reserved fields should only be done with previously read data.
Offset
Register Name
Reset
Page No.
01h–00h
Vendor ID (API NetWorks, Inc.)
14D9h
5-6
03h–02h
Device ID
0010h
05h–04h
Command
0000h
07h–06h
Status
0010h
08h
Revision ID
See Note.
0Bh–09h
Class Code
060400h
0Ch
Cacheline
00h
0Dh
Primary Latency Timer
00h
0Eh
Header Type
01h
0Fh
BIST
00h
13h–10h
Base Address Register 0
00000000h
Table 5.1 Function 0
Configuration Registers