Intel
®
81341 and 81342—Messaging Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
450
Order Number: 315037-002US
4.9.29
MU MSI-X Pending Bits Array Register - M_MPBAR
The MU MSI-X Pending Bits Array Register contains the contains the pending bits for
the eight MU interrupt sources. When an entry in the MSI-X table is masked in the
Vector Control Register, the software may service that interrupt request by polling the
pending bit.
Note:
The M_MPBAR register is not reset with an internal bus reset.
4.9.30
MSI Capability Identifier Register - Cap_ID
The MSI Capability Identifier Register bits adhere to the definitions in the PCI Local Bus
Specification, Revision 2.2. This register in the PCI Interface Extended Capability
header identifies the type of Extended Capability contained in that header. The value of
05H in this field identifies the function as message signaled interrupt capable.
Note:
Refer to the Peripheral Registers Chapter for the default internal bus address. This
register is part of the configuration space of the Address Translation Unit that is setup
as an endpoint.
Table 293. MU MSI-X Pending Bits Array Register - M_MPBAR
Bit
Default
Description
31:08
0000 000H Reserved.
07:00
00000000
2
Pending Bits Array: Any bit that is set indicates that the associated MSI-X message is scheduled to be
sent. When an associated entry in the MSI-X table is masked using the mask bit in the Vector Control
Register, software can service the interrupt based on polling the associated pending bit.
PCI
IOP
Attributes
Attributes
28
24
20
16
12
8
4
0
31
rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv ro ro ro ro ro ro ro ro
rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv rv ro ro ro ro ro ro ro ro
Attribute Legend:
RV = Reserved
PR = Preserved
RS = Read/Set
RW = Read/Write
RC = Read Clear
RO = Read Only
NA = Not Accessible
M_MPBAR
internal bus address
offset
5800H
M_MPBAR
MU/PCI Base Address
Offset
1800H
Table 294. MSI Capability Identifier Register - MSI_Cap_ID
Bit
Default
Description
07:00
05H
MSI_Cap_Id
- This field with its 05H value identifies this item in the linked list of Extended Capability
Headers as being the message signaled interrupt capability item.
PCI
IOP
Attributes
Attributes
7
4
0
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
ro
Attribute Legend:
RV = Reserved
PR = Preserved
RS = Read/Set
RW = Read/Write
RC = Read Clear
RO = Read Only
NA = Not Accessible
PCI Configuration Offset
A0H
Internal Bus Address Offset
0A0H