Intel C2518 FH8065501516710 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

Datasheet, Vol. 2 of 3

September 2014

348

Order Number: 330061-002US

This section is informational. The hardware does not inspect or decode any portion of 

an Management Component Transport Protocol (MCTP) packet.

MCTP messages with SMBus packet headers can encapsulate data from various 

protocols like ASF, Network, etc. The command code in the packet (byte 1) identifies 

this packet as MCTP and the firmware takes appropriate action. Refer to the MCTP 

Specification for further details on the protocol.

The following information is contained in the MCTP Specification but is reproduced here 

for completeness.

0

Destination Slave 

Address

For the local SMBus, slave address for the target device. 
Bit 0 is always 0 since all MCTP messages are writes.

1

Command Code

Command code indicating MCTP packet. This value is fixed at 0Fh.

2

Length

Length of the Block Write. Analogous to the Byte Count field of the SMBus Block 

Write except length is not limited to 32 bytes. This count indicates the number of 

bytes to follow in the current message without counting the PEC byte.

3

Slave Address

Bits [7:1]: For the local SMBus, the slave address of the message initiator. This 

initiator is a repeater and cannot be assumed to be the original initiator.
Bit 0: Reserved, always 1b.

4

Header Type

Bits [7:4]: Reserved
Bits [3:0]: MCTP Version: 1h for all MCTP device compliant to the MCTP 1.0 

Specification.

5

Destination 

Endpoint ID

Unique ID on the System for the destination of the message. This ID reflects the 

final destination of the message.
Reserved Values:
0 = Local Bus only. Terminate at Receiver.

1 = Route to Root Management Controller.
2-7 = Reserved for future definition.

6

Source Endpoint 

ID

Unique ID on the System for the originator of the message. This ID reflects the 

true initiator of the message.