Intel C2550 FH8065401488912 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

Datasheet, Vol. 2 of 3

September 2014

382

Order Number: 330061-002US

The PECI uses a simple structure of message header and a write-read protocol. All PECI 

devices have a command field. The following section describes PECI protocol. Refer to 

the RS - Platform Environment Control Interface (PECI) Specification, Revision 3.0 for 

details.

The header conveys to the target device how many bytes master intends to send and 

how many it expects to receive back. The first byte of the write data is interpreted as a 

command to the device and must be present in all messages. The Ping() command is 

the only exception to this rule. Additional bytes are written to convey sub commands or 

to send data to the device. A zero value in the Read Length field means no data is read 

from the target device. See 

 for the PECI Message Header. In the figure, N 

bytes are to be written to the target and M bytes are to be read back from the target.

In the PECI Message Header, the Address Timing Negotiation (NT) and Message Timing 

Negotiation (MT) bits described in RS - Platform Environment Control Interface (PECI) 

Specification, Revision 3.0 are not implemented. It is the responsibility of the BMC to 

not include these timing bits in the header.

8

Target Address

1 8

Write Length

8

Read Length

8

Data Bytes [0...N]

00

0

N

M