Intel
®
81341 and 81342—Messaging Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
454
Order Number: 315037-002US
4.9.34
Message Upper Address Register - Message_Upper_Address
The Message Upper Address register is set during system initialization when system
software wishes to place the MSI address location above the 4G address boundary.
When this register is set to a non-zero value, the 81341 and 81342 generates a dual
address cycle for the MSI write command and uses the contents of this register as the
upper 32-bits of that address.
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 298. Message Upper Address Register - Message_Upper_Address
Bit
Default
Description
31:00
00000000H Message Upper Address - Upper 32 bits of a 64-bit PCI address. This value is set by system software.
PCI
IOP
Attributes
Attributes
28
24
20
16
12
8
4
0
31
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Attribute Legend:
RV = Reserved
PR = Preserved
RS = Read/Set
RW = Read/Write
RC = Read Clear
RO = Read Only
NA = Not Accessible
PCI Configuration Offset
A8H
Internal Bus Address Offset
0A8H