Digi NS9750 - Manual (Page 437)

w w w . d i g i e m b e d d e d . c o m 4 1 3
P C I - t o - A H B B r i d g e
Bridge Configuration registers
Table 254 shows the standard PCI configuration registers that are supported by the
PCI-to-AHB bridge. These registers can be 8-, 16-, or 32-bits wide, as indicated in the
table. The size of the transfer on the AHB bus determines which bytes are written.
All configuration registers must be accessed as 32-bit words and as single accesses
only. Bursting is not allowed.
The registers are described briefly in this chapter. For more information about each
register, see your PCI documentation.
Note:
The register number refers to the
REGISTER_NUMBER
field in the
Configuration Address Port register (see Table 253, “CONFIG_ADDR
register,” on page 411).
Register
number
[31:24] [23:16] [15:08] [07:00]
0x00 Device ID
1
Vendor ID
1
0x01 Status Command
0x02 Class code
1
Revision ID
1
0x03 BIST Header Latency timer Cache size
0x04 Base address 0
0x05 Base address 1
0x06 Base address 2
0x07 Base address 3
0x08 Base address 4
0x09 Base address 5
0x0A CardBus CIS pointer
0x0B Subsystem ID 1 Subsystem vendor ID 1
0x0C Expansion ROM
0x0D Reserved
0x0E Reserved
0x0F Max_Lat
1
Min_Gnt
1
Interrupt pin
1
Interrupt Line
Table 254: PCI/bridge configuration registers