Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
345
Address Translation Unit (PCI Express)—Intel
®
81341 and 81342
3.16.56 PCI Express Next Item Pointer Register - PCIE_NXTP
The Next Item Pointer Register bits adhere to the definitions in the PCI Local Bus
Specification, Revision 2.3. This register describes the location of the next item in the
function’s capability list.
By default, the PCI Express capability is the last capabilities list for the 81341 and
81342, thus this register defaults to 00H.
However, this register may be written to 90H prior to host configuration to include the
VPD capability located at off-set 90H.
Warning:
Writing this register to any value other than 00H (default) or 90H is not supported and
may produce unpredictable system behavior.
In order to insure that this register is written prior to host configuration, the 81341 and
81342 must be initialized at
P_RST#
assertion to Retry Type 0 configuration cycles (bit
2 of PCSR). Typically, the Intel XScale
®
processor would be enabled to boot
immediately following
P_RST#
assertion in this case (bit 1 of PCSR), as well. Please
see
Section 3.16.41, “PCI Configuration and Status Register - PCSR” on page 331
for
more details on the 81341 and 81342’s initialization modes.
Table 190. PCI Express Next Item Pointer Register - PCIE_NXTP
Bit
Default
Description
07:00
00H
Next_ Item_ Pointer
- This field provides an offset into the function’s configuration space pointing to the
next item in the function’s capability list. Since the PCI Express capabilities are the last in the linked list
of extended capabilities in the 81341 and 81342, the register is set to 00H.
However, this field may be written prior to host configuration with 90H to extend the list to include the
VPD extended capabilities header.
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
Internal Bus Address Offset
+0D1H