A Controller Area Network (CAN) node consists of a high-powered
microcontroller, a low standby power regulator, a CAN bus transceiver,
and a minimal CAN message buffer for storing received messages. Low power
standby operation allows for the controller to power off, while the
transceiver and regulator are operated in standby. The
transceiver/regulator will enter run mode after the first symbol of a
received CAN message is validated off the bus. As the original CAN
message is received, it is buffered in the message buffer and, after
stored, a status register is set to indicate the full message has been
received. Once the controller has stabilized out of a wake-up mode, it
retrieves the stored message and acts accordingly. The CAN message buffer
is coupled to the controller by an system packet interface (SPI)
interface for transmission of a controller wake-up command and retrieval
of a buffered message.