Intel CONTROLLERS 413808 - Manual (Page 159)

Intel ® 413808 and 413812 I/O Controllers in TPER Mode
October 2007 Developer’s Manual
Order Number: 317805-001US 159
Address Translation Unit (PCI-X)—Intel
®
413808 and 413812
2.14.17 Inbound ATU Base Address Register 2 - IABAR2
The Inbound ATU Base Address Register 2 (IABAR2) together with the Inbound ATU
Upper Base Address Register 2 (IAUBAR2) defines the block of memory space
addresses where the inbound translation window 2 begins. The inbound ATU decodes
and forwards the bus request to the 4138xx internal bus with a translated address to
map into 4138xx local memory. The IABAR2 and IAUBAR2 (Memory Space only) define
the base address and describes the required address block size; see Section 2.14.23,
“Determining Block Sizes for Base Address Registers” on page 164 . Bits 31 through 8 of
the IABAR2 is either read/write bits or read only with a value of 0 depending on the
value located within the IALR2. This configuration allows the IABAR2 to be programmed
per PCI Local Bus Specification, Revision 2.3.
The programmed value within the base address register must comply with the PCI
programming requirements for address alignment. Refer to the PCI Local Bus
Specification, Revision 2.3 for additional information on programming base address
registers.
Warning:
When IALR2 is cleared prior to host configuration, the user should also clear the
Prefetchable Indicator and the Type Indicator. Assuming IALR2 is not cleared:
e. Since non prefetchable memory windows can never be placed above the 4 Gbyte address boundary,
when the Prefetchable Indicator is cleared prior to host configuration, the user should also set the
Type Indicator for 32 bit addressability.
f. For compliance to the PCI-X Protocol Addendum to the PCI Local Bus Specification, Revision 2.0,
when the Prefetchable Indicator is set prior to host configuration, the user should also set the Type
Indicator for 64 bit addressability. This is the default for IABAR2.
Table 43. Inbound ATU Base Address Register 2 - IABAR2
Bit Default Description
31:12 00000H
Translation Base Address 2 - These bits define the actual location the translation function is to respond
to when addressed from the PCI bus.
11:04 000H Reserved.
03 0
2
Prefetchable Indicator - When set, defines the memory space as prefetchable.
02:01 00
2
Type Indicator - Defines the width of the addressability for this memory window (Memory Space
Indicator = 0):
00 - Memory Window is locatable anywhere in 32 bit address space
10 - Memory Window is locatable anywhere in 64 bit address space
00 0
2
Memory Space Indicator - This bit field describes memory or I/O space base address. The ATU does not
occupy I/O space, thus this bit must be zero.
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
rv
rv
rv
rv
rv
rv
rv
rv
rv
rv
rv
rv
rv
rv
rv
rv
rw
ro
rw
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
Register Offset
+020H