Specification Sheet

Interfaces
68 Intel
®
Xeon
®
Processor E5-1600/E5-2600/E5-4600 v2 Product Families
Datasheet Volume One of Two
completion code. Alternatively, reads to unimplemented or hidden registers may return
a completion code of 0x90 indicating an invalid request. It is also possible that reads to
function 0 of non-existent IIO devices issued prior to BIOS POST may return all ‘0’s
with a passing completion code. PECI originators can access this space even prior to
BIOS enumeration of the system buses. There is no read restriction on accesses to
locked registers.
PCI configuration addresses are constructed as shown in Figure 2-46. Under normal in-
band procedures, the Bus number would be used to direct a read or write to the proper
device. PECI reads to the processor IIO devices should specify a bus number of ‘0000’
and reads to the rest of the processor uncore should specify a bus number of ‘0001’ for
bits [23:20] in Figure 2-46. Any request made with a bad Bus number is ignored and
the client will respond with all ‘0’s and a ‘passing’ completion code.
2.5.2.9.1 Command Format
The RdPCIConfigLocal() format is as follows:
Write Length: 0x05
Read Length: 0x02 (byte),
0x03 (word), 0x05 (dword)
Command: 0xe1
Description: Returns the data maintained in the PCI configuration space within the
processor at the requested PCI configuration address. The Read Length dictates the
desired data return size. This command supports byte, word and dword responses as
well as a completion code. All command responses are prepended with a completion
code that includes additional pass/fail status information. Refer to Section 2.5.5.2 for
details regarding completion codes.
Note: The 3-byte PCI configuration address and read data field defined in Figure 2-47 are sent in standard
PECI ordering with LSB first and MSB last.
Figure 2-46. PCI Configuration Address for local accesses
20 19 15 1114 12 0
23
DeviceBus Function Register
Figure 2-47. RdPCIConfigLocal()
01 2 3
Byte #
FCS
12
7
9
Completion
Code
LSB PCI Configuration Address MSB
10
Write Length
0x05
LSB Data (1, 2 or 4 bytes) MSB
5
Cmd Code
0xe1
14
Read Length
{0x02,0x03,0x05}
68
Host ID[7:1] &
Retry[0]
Client Address
13
4
11
FCS
Byte
Definition