Intel CM8063501287403 User Manual

Page of 232
Intel® Xeon® Processor E5-1600 v2/E5-2600 v2 Product Families
31
Datasheet Volume One of Two
 
Interfaces
PECI permits writes to certain Memory Controller RAS-related registers in the processor 
PCI configuration space. Details are covered in 
2.5.2
Client Command Suite
PECI command requires at least one frame check sequence (FCS) byte to ensure 
reliable data exchange between originator and client. The PECI message protocol 
defines two FCS bytes that are returned by the client to the message originator. The 
first FCS byte covers the client address byte, the Read and Write Length bytes, and all 
bytes in the write data block. The second FCS byte covers the read response data 
returned by the PECI client. The FCS byte is the result of a cyclic redundancy check 
(CRC) of each data block. 
2.5.2.1
Ping()
Ping() is a required message for all PECI devices. This message is used to enumerate 
devices or determine if a device has been removed, been powered-off, and so forth. A 
Ping() sent to a device address always returns a non-zero Write FCS if the device at the 
targeted address is able to respond. 
2.5.2.1.1
Command Format
The Ping() format is as follows:
Write Length: 0x00
Read Length: 0x00
An example Ping() command to PECI device address 0x30 is shown below.
2.5.2.2
GetDIB()
The processor PECI client implementation of GetDIB() includes an 8-byte response and 
provides information regarding client revision number and the number of supported 
domains. All processor PECI clients support the GetDIB() command.
2.5.2.2.1
Command Format
The GetDIB() format is as follows:
Write Length: 0x01
Figure 2-3. Ping()
Byte #
Byte 
Definition
0
Client Address
1
Write Length
0x00
2
Read Length
0x00
3
FCS
Figure 2-4. Ping() Example
Byte #
Byte 
Definition
0
0x30
1
0x00
2
0x00
3
0xe1