Apparatus for a controller area network

An apparatus for a controller area network, CAN, node, the node comprising a CAN controller and a CAN transceiver that is configured to couple to a CAN bus, the apparatus comprising a CAN protocol decoder and circuitry, the apparatus configured to:

• receive an RX-bitstream comprising a bitstream generated from signalling received from the CAN bus by the CAN transceiver for the CAN controller;
• receive a TX-bitstream comprising a bitstream generated by the CAN controller for receipt by the CAN transceiver for transmission of signalling on the CAN bus;
• wherein the CAN protocol decoder is configured to receive a bitstream based on the TX-bitstream for decoding CAN frames therein for monitoring of the CAN controller;
• and wherein the circuitry is configured to:
• detect an idle state that occurs between CAN frames based on at least one of the RX-bitstream and the TX-bitstream;
• based on the detection of the idle state, modify the bitstream received by the CAN protocol decoder such that it includes a Start-of-Frame bit further based on detection of a Start-of-frame bit in the RX-bitstream.