Intel
®
81341 and 81342—Address Translation Unit (PCI-X)
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
172
Order Number: 315037-002US
2.13.25 ATU Interrupt Pin Register - ATUIPR
ATU Interrupt Pin Register bit definitions adhere to PCI Local Bus Specification,
Revision 2.3. This register identifies the interrupt pin the ATU and Messaging Unit
interface uses. The 81341 and 81342 is, a PCI single-function device and, as such,
generates only one interrupt output. The interrupt output is for the Messaging Unit on
INTA#
.
2.13.26 ATU Minimum Grant Register - ATUMGNT
ATU Minimum Grant Register bit definitions adhere to PCI Local Bus Specification,
Revision 2.3. This register specifies the burst period the device requires in increments
of 8 PCI clocks.
This register and the ATU Maximum Latency register are information-only registers
which the configuration uses to determine how often a bus master typically requires
access to the PCI bus and the duration of a typical transfer when it does acquire the
bus. This information is useful in determining the values to be programmed into the
bus master latency timers and in programming the algorithm to be used by the PCI bus
arbiter.
Table 48. ATU Interrupt Pin Register - ATUIPR
Bit
Default
Description
07:00
01H
Interrupt Used - A value of 01H signifies that the ATU interface unit uses
INTA#
as the interrupt pin.
PCI
IOP
Attributes
Attributes
7
4
0
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
+03DH
Table 49. ATU Minimum Grant Register - ATUMGNT
Bit
Default
Description
07:00
80H
This register specifies how long a burst period the device needs in increments of 8 PCI clocks.
PCI
IOP
Attributes
Attributes
7
4
0
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
+003EH