SAM C21 CAN Overview

Last modified by Microchip on 2023/11/09 09:01


The SAM C20/C21 family of devices includes up to two Controller Area Network (CAN) modules, which facilitate a robust industrial communications protocol used in automotive, aerospace, maritime, railway vehicles, industrial automation, and medical equipment applications.

The CAN module performs communication according to the ISO 11898-2 (Bosch CAN specification 2.0 part A,B) and to the Bosch CAN FD specification V1.0. The message storage is intended to be a single- or dual-ported Message RAM outside of the module.

In order to connect the SAM C21 to the CAN bus, an external CAN transceiver is required. The bus should be terminated at both ends with 120 Ω resistors. Here is a typical CAN bus layout:

samc21 can bus layout


  • Conform with CAN protocol version 2.0 part A, B and ISO 11898-2
  • CAN FD with up to 64 data bytes supported
  • CAN Error Logging
  • AUTOSAR optimized
  • SAE J1939 optimized
  • Two configurable Receive FIFOs
  • Separate signaling on reception of High Priority Messages
  • Up to 64 dedicated Receive Buffers and up to 32 dedicated Transmit Buffers
  • Configurable Transmit FIFO, Transmit Queue, Transmit Event FIFO
  • Direct Message RAM access for CPU
  • Programmable loop-back test mode
  • Maskable module interrupts
  • Power-down support; Debug on CAN support
  • Transfer rates:
    • 1 Mb/s for CAN 2.0 mode
    • 10 Mb/s for CAN-FD mode

Block Diagram

samc21 can block diagram