Client Command Suite; Ping(); Ping() Example - Intel BX80619I73820 Design Manual

PECI Interface
7.1.2

Client Command Suite

Each 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.
7.1.2.1

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 on. 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.
7.1.2.1.1 Command Format
The Ping() format is as follows:
Write Length: 0x00
Read Length: 0x00
Figure 7-1. Ping()
An example Ping() command to PECI device address 0x30 is shown below.
Figure 7-2.

Ping() Example

Thermal/Mechanical Specifications and Design Guide
Byte # 0
Client Address
Byte
Definition
Byte # 0
Byte
0x30
Definition
1 2
Write Length Read Length
0x00 0x00
1
0x00 0x00
3
FCS
2 3
0xe1
55