Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
223
Address Translation Unit (PCI-X)—Intel
®
81341 and 81342
2.13.79 Outbound Configuration Cycle Address Register - OCCAR
The Outbound Configuration Cycle Address Register is used to hold the 32-bit PCI
configuration cycle address. The Intel XScale
®
processor writes the PCI configuration
cycles address, which enables outbound configuration read or write. The Intel XScale
®
processor then performs a read or write to the Outbound Configuration Cycle Data
Register to initiate the configuration cycle on the PCI bus.
Note:
Bits 15:11 of the configuration cycle address for Type 0 configuration cycles are defined
differently for Conventional versus PCI-X modes. When 81341 and 81342 software
programs the OCCAR to initiate a Type 0 configuration cycle, the OCCAR should always
be loaded based on the PCI-X definition for the Type 0 configuration cycle address.
When operating in Conventional mode, the 81341 and 81342 clears bits 15:11 of the
OCCAR prior to initiating an outbound Type 0 configuration cycle. See the PCI-X
Protocol Addendum to the PCI Local Bus Specification, Revision 2.0 for details on the
two formats.
Table 102. Outbound Configuration Cycle Address Register - OCCAR
Bit
Default
Description
31:00 0000 0000H Configuration Cycle Address - These bits define the 32-bit PCI address used during an outbound
configuration read or write cycle.
PCI
IOP
Attributes
Attributes
28
24
20
16
12
8
4
0
31
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
rw
ro
Attribute Legend:
RV = Reserved
PR = Preserved
RS = Read/Set
RW = Read/Write
RC = Read Clear
RO = Read Only
NA = Not Accessible
Register Offset
+330H