CAN Protocol Engine

The CAN Protocol Engine is a core component within a CAN Bus Controller that handles the low-level protocol operations of the CAN network. It manages frame transmission and reception (including data, remote, error, and overload frames), implements bit timing and synchronization, performs error detection and signaling, handles arbitration for bus access, and ensures compliance with the CAN protocol specifications (e.g., ISO 11898). It serves as the interface between the microcontroller and the physical CAN transceiver, enabling reliable, real-time serial communication in automotive and embedded control applications.

The engine operates by receiving data from a host microcontroller, packaging it into CAN frames with appropriate identifiers and control bits, and serially transmitting the bits onto the CAN bus via a transceiver. It monitors the bus state, synchronizes to the bit stream using phase buffers, and performs bit-stuffing for synchronization. During reception, it decodes incoming frames, checks for errors (CRC, form, bit errors), and filters messages based on identifier masks. It handles arbitration by continuously monitoring the bus during transmission—if a dominant bit is detected while transmitting a recessive bit, it loses arbitration and switches to receiver mode.