Can Protocol; Frame Format - NEC V850ES/F 3-L Series User Manual

32-bit single-chip microcontroller

Table of Contents

CAN Controller (CAN)

18.2 CAN Protocol

Physical layer

CAN (Controller Area Network) is a high-speed multiplex communication

protocol for real-time communication in automotive applications (class C). CAN

is prescribed by ISO 11898. For details, refer to the ISO 11898 specifications.

The CAN specification is generally divided into two layers: a physical layer and

a data link layer. In turn, the data link layer includes logical link and medium

access control. The composition of these layers is illustrated below.

Logical link control (LLC)

Medium access control (MAC)

Composition of layers

CAN Controller specification

Standard format frame

• The standard format frame uses 11-bit identifiers, which means that it can

handle up to 2,048 messages.

Extended format frame

• The extended format frame uses 29-bit (11 bits + 18 bits) identifiers, which

increases the number of messages that can be handled to 2,048 × 2

• An extended format frame is set when "recessive level" (CMOS level of "1")

is set for both the SRR and IDE bits in the arbitration field.

User's Manual U18743EE1V2UM00

Acceptance filtering

Overload report

Recovery management

Data capsuled/not capsuled

Frame coding (stuffing/no stuffing)

Medium access management

Error detection

Error report

Acknowledgement

Seriated/not seriated

Prescription of signal level and bit description