CAN CC

CAN CC (Classical CAN) is a serial broadcast network standard for embedded control systems, standardized at the data link layer in ISO 11898-1. Nodes transmit frames with an 11-bit or 29-bit identifier; lower identifier values have higher priority and simultaneous access is resolved by bit-wise arbitration. It includes error detection, error frames and fault confinement to maintain data consistency.

Source checked4/4 values · 2026-10-25

Specification

1 source

Transports	serial
Architecture	producer consumer
Encoding	binary
Standard body	ISO
Standard ref	ISO 11898-1

Study notes

CAN CC uses broadcast communication; each data frame carries a CAN identifier intended to be unique in the network and to indicate content and access priority.
The identifier is an 11-bit value in CBFF or a 29-bit value in CEFF; the lowest identifier value has the highest priority.
Simultaneous access is resolved by bit-wise arbitration using dominant and recessive states; nodes that lose arbitration become receivers.
The DLC indicates the data field length in bytes; the data field carries 0 to 8 application data bytes.
The protocol defines five error detection mechanisms: CRC, frame check, ACK error, bit monitoring and bit stuffing.
Bit coding is NRZ; bit stuffing inserts a complementary stuff bit after five consecutive bits of the same value.
A 3-bit intermission field is the minimum separation between consecutive frames; the inter-frame space may also include bus idle time and an 8-bit suspend transmission for an error-passive node.
Extended frame format has at least 20 bit times longer network latency, requires about 20% more bandwidth and has lower error detection performance because the 15-bit CRC polynomial is optimized for frame lengths up to 112 bit.

Safety

Error frames abort an ongoing transmission when any node detects an error, forcing other nodes to detect the error and maintaining network-wide data consistency.
Fault confinement switches off the CAN interface of a faulty node (bus-off state) to prevent permanent disturbance of CAN communication.
After an error frame, receivers expect retransmission of the aborted data frame.
Older CAN CC implementations may only accept the base frame format or only tolerate the extended frame format; since 2003 implementations shall handle both formats.