/**
 * @defgroup sys_can CAN (Controller Area Network)
 * @ingroup net
 * @brief RIOT CAN stack
 *
 * This module is a full CAN stack integrated to RIOT.
 * It includes a low-level interface, a data link layer, an ISO-TP layer and
 * a user interface.
 *
 * The low-level interface, candev, must be implemented by controler drivers.
 * The optional transceiver support can also be activated. Transceiver drivers must
 * then implement the trx_can interface.
 *
 * The data link layer is built around a device thread (one thread per CAN device),
 * and a common part. The common part is composed of the dll interface, for low-level
 * calls (from the device) and the raw interface for upper-level calls.
 * Internally it also uses the pkt module to allocate frames and the router module
 * to manage CAN filters.
 *
 * The ISO-TP layer uses the data link layer to send and receive CAN frames.
 *
 * Finally, the connection layer is the user interface to send and receive raw
 * CAN frames or ISO-TP datagrams.
 *
 * @see drivers_can
 */