Wrpciconfiglocal() - Intel BX80619I73820 Design Manual

Table 7-14. RdPCIConfigLocal() Response Definition (Sheet 2 of 2)
Response
CC: 0x81
CC: 0x82
CC: 0x90
CC: 0x91
7.1.4.12

WrPCIConfigLocal()

The WrPCIConfigLocal() command provides sideband write access to the PCI
configuration space that resides within the processor. PECI originators may conduct a
device/function/register enumeration sweep of this space by issuing reads in the same
manner that BIOS would. PECI originators can access this space even before BIOS
enumeration of the system buses. The exact listing of supported devices and functions
for writes using this command on the processor is defined in
Because a WrPCIConfigLocal() command results in an update to potentially critical
registers inside the processor, it includes an Assured Write FCS (AW FCS) byte as part
of the write data payload. In the event that the AW FCS mismatches with the client-
calculated FCS, the client will abort the write and will always respond with a bad write
FCS.
PCI Configuration addresses are constructed as shown in
command is subject to the same address configuration rules as defined in
Section 7.1.4.11. PCI configuration writes may be issued in byte, word or dword
granularity.
7.1.4.12.1 Command Format
The WrPCIConfigLocal() format is as follows:
Write Length: 0x07 (byte), 0x08 (word), 0x0a (dword)
Read Length: 0x01
Command: 0xE5
AW FCS Support: Yes
Description: Writes the data sent to the requested register address. Write Length
dictates the desired write granularity. The command always returns a completion code
indicating pass/fail status. Refer to
86
Response timeout. The processor is not able to allocate resources for servicing this
command at this time. Retry is appropriate.
The processor hardware resources required to service this command are in a low power
state. Retry may be appropriate after modification of PECI wake mode behavior if
appropriate.
Unknown/Invalid Request
PECI control hardware, firmware or associated logic error. The processor is unable to
process the request.
Section 7.1.7.2
Meaning
Table 7-20.
Figure 7-41. The write
for details on completion codes.
Thermal/Mechanical Specifications and Design Guide
PECI Interface