301467-005 Datasheet, PDF (148/426 Pages) Intel Corporation – Express Chipset

Host-PCI Express* Bridge Registers (D1:F0)
(Intel® 82915G/82915P/82915PL Only)
R
8.1.28
MC—Message Control (D1:F0)
PCI Device:
Address Offset:
Default Value:
Access:
Size:
1
92h
0000h
RO, R/W
16 bits
System software can modify bits in this register, but the device is prohibited from doing so.
If the device writes the same message multiple times, only one of those messages is guaranteed to
be serviced. If all of them must be serviced, the device must not generate the same message again
until the driver services the earlier one.
Bit
Access &
Default
Description
15:8
Reserved
7
RO
64-bit Address Capable: Hardwired to 0 to indicate that the function does not
0b
implement the upper 32 bits of the Message Address register and is incapable of
generating a 64-bit memory address.
6:4
R/W
Multiple Message Enable (MME): System software programs this field to
000b
indicate the actual number of messages allocated to this device. This number will
be equal to or less than the number actually requested.
000 = 1 message allocated
001–111 = Reserved
3:1
RO
Multiple Message Capable (MMC): System software reads this field to
000b
determine the number of messages being requested by this device.
000 = 1 message requested
001–111 = Reserved
0
R/W
MSI Enable (MSIEN) Controls the ability of this device to generate MSIs.
0b
0 = MSI will not be generated.
1 = MSI will be generated when we receive PME or HotPlug messages. INTA will
not be generated and INTA Status (PCISTS1[3]) will not be set.
148
Datasheet