IBM Intel Xeon X5647 81Y6551 User Manual

Product codes
81Y6551
Page of 186
Intel
®
 Xeon
®
 Processor 5600 Series Datasheet Volume 1
139
Thermal Specifications
7.3.2.4
PCIConfigRd()
The PCIConfigRd() command gives sideband read access to the entire PCI configuration 
space maintained in the processor. This capability does not include support for route-
through to downstream devices or sibling processors. The exact listing of supported 
devices, functions, and registers can be found in the Intel® Xeon® Processor 5600 
Series Datasheet, Volume 2
. PECI originators may conduct a device/function/register 
enumeration sweep of this space by issuing reads in the same manner that BIOS 
would. A response of all 1’s indicates that the device/function/register is 
unimplemented.
PCI configuration addresses are constructed as shown in the following diagram. Under 
normal in-band procedures, the Bus number (including any reserved bits) would be 
used to direct a read or write to the proper device. Since there is a one-to-one mapping 
between any given client address and the bus number, any request made with a non-
zero Bus number is ignored and the client will respond with a ‘pass’ completion code 
but all 0’s in the data. The only legal bus number is 0x00. The client will return all 1’s in 
the data response and ‘pass’ for the completion code for all of the following conditions:
• Unimplemented Device
• Unimplemented Function
• Unimplemented Register
PCI configuration reads may be issued in byte, word, or dword granularities.
7.3.2.4.1
Command Format
The PCIConfigRd() format is as follows:
Write Length: 5
Read Length: 2 (byte data), 3 (word data), 5 (dword data)
Command: 0xc1
Multi-Domain Support: Yes (see 
Description: Returns the data maintained in the PCI configuration space at the PCI 
configuration address sent. The Read Length dictates the desired data return size. This 
command supports byte, word, and dword responses as well as a completion code. All 
Table 7-21. GetTemp() Response Definition
Response
Meaning
General Sensor Error (GSE)
Thermal scan did not complete in time. Retry is appropriate.
0x0000
Processor is running at its maximum temperature or is currently being reset.
All other data
Valid temperature reading, reported as a negative offset from the TCC 
activation temperature.
Figure 7-20. PCI Configuration Address
31
Reserved
27
28
20
19
15
11
14
12
0
Bus
Device
Function
Register