To Next Page

To Previous Page

Enhanced Controller Area Network (eCAN)

Principles of Operation

 Data messages transmitted are identifier based,

not address based

 Content of message is labeled by an identifier that

is unique throughout the network

 (e.g. rpm, temperature, position, pressure, etc.)

 All nodes on network receive the message and

each performs an acceptance test on the identifier

 If message is relevant, it is processed (received);

otherwise it is ignored

 Unique identifier also determines the priority of the

message

 (lower the numerical value of the identifier, the higher the

priority)

 When two or more nodes attempt to transmit at the

same time, a non-destructive arbitration technique

guarantees messages are sent in order of priority

and no messages are lost

Non-Destructive Bitwise Arbitration

 Bus arbitration resolved via arbitration with

wired-AND bus connections

 Dominate state (logic 0, bus is high)

 Recessive state (logic 1, bus is low)

Node A wins

arbitration

CAN Bus

Node A

Node B

Node C

Start

Bit

Node B loses

arbitration

Node C loses

arbitration

11 - 22 C28x - Communications

Texas Instruments C28 Series Student Guide

Other manuals for Texas Instruments C28 Series