Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
331
Address Translation Unit (PCI Express)—Intel
®
81341 and 81342
3.16.41 PCI Configuration and Status Register - PCSR
The PCI Configuration and Status Register has additional bits for controlling and
monitoring various features of the PCI Express interface.
Warning:
The PCI Express Bus Number and Device Number are used to form the Requestor/
Completer ID and should only be changed when operating as a Root Complex. These
fields are updated whenever a type 0 configuration write targets the IOP. System
instability may result when the Bus/Device numbers are modified while operating as an
endpoint.
Table 175. PCI Configuration and Status Register - PCSR (Sheet 1 of 2)
Bit
Default
Description
31:24
00H
PCI Express Bus Number
23:19
0_0000
2
PCI Express Device Number
18:16
000
2
PCI Express Function Number
15
0
2
Outbound Transaction Queue Busy:
0 = Outbound Transaction Queue Empty
1 = Outbound Transaction Queue Busy
Note:
This tracks outbound transactions and includes the Outbound Non-Posted, Outbound Posted,
and Inbound Completion queues.
14
0
2
Inbound Transaction Queue Busy:
0 = Inbound Transaction Queue Empty
1 = Inbound Transaction Queue Busy
Note:
This tracks inbound transactions and includes the Inbound Non-Posted, Inbound Posted, and
Outbound Completions queues.
13
Varies with
external state
of the
PCIE_RC#
strap.
PCI Express Root Complex mode
0 = PCI Express Root Complex enabled
1 = PCI Express Root Complex disabled (end point mode).
12
0
Link Layer Retry Buffer (LLRB) Busy.
0 = LLRB Empty
1 = LLRB Busy
11:10
00
2
Reserved
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
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
rv
rv
rv
rv
rw
rw
rw
rw
rc
rc
rw
rw
rv
rv
rv
rv
rv
rv
rw
ro
co
co
co
co
Attribute Legend:
RV = Reserved
PR = Preserved
RS = Read/Set
RW = Read/Write
RC = Read Clear
RO = Read Only
CO = Clear Only
Internal Bus Address Offset
+074H