Outbound configuration cycle data, Register - occdr, Address translation unit (pci-x)—intel – Intel CONTROLLERS 413808 User Manual

Page 219: Bit default description, Intel

Intel

413808 and 413812 I/O Controllers in TPER Mode

October 2007

Developer’s Manual

Order Number: 317805-001US

219

Address Translation Unit (PCI-X)—Intel

413808 and 413812

2.14.80 Outbound Configuration Cycle Data Register - OCCDR

The Outbound Configuration Cycle Data Register is used to initiate a configuration read

or write on the PCI bus. The register is logical rather than physical meaning that it is an

address not a register. The Intel XScale

processor reads or writes the data registers

memory-mapped address to initiate the configuration cycle on the PCI bus with the

address found in the OCCAR. For a configuration write, the data is latched from the

internal bus and forwarded directly to the OWQ. For a read, the data is returned

directly from the ORQ to the Intel XScale

processor and is never actually entered into

the data register (which does not physically exist).
The OCCDR is only visible from 4138xx internal bus address space and appears as a

reserved value within the ATU configuration space.

2.14.81 Outbound Configuration Cycle Function Number - OCCFN

This register contains the Requester ID function number used for all outbound

configuration requests. This field is also used to determine where errors get logged.
For 4138xx the function number should be 0 for endpoint usage and match the ATUX

function number (readable in

“PCI-X Status Register - PCIXSR”

) for Root Complex

modes.

Table 107. Outbound Configuration Cycle Data Register - OCCDR

Bit

Default

Description

31:00 0000 0000H Configuration Cycle Data - Define the data used during an outbound configuration read or write cycle.

PCI

IOP

Attributes

Attribute Legend:

RV = Reserved

PR = Preserved

RS = Read/Set

RW = Read/Write

RC = Read Clear

RO = Read Only

NA = Not Accessible

+334H

Table 108. Outbound Configuration Cycle Function Number Register - OCCFN

Bit