CAN bus controller

Abstract

The invention discloses a CAN bus controller. The CAN bus controller comprises a housing, a register management logic module and a detection control module, and the register management logic module and the detection control module are installed in the housing. A watchdog timer and a clock check timer are integrated in the detection control module. The watchdog timer is used for carrying out zero clearing when a microprocessor carries out read-write operation on the register management logic module, and carrying out counting in dependence on the frequency of an external crystal oscillator clock, and generating an overflow interrupt signal when the counter is overflowed; the clock check timer is used for counting the frequency of the external crystal oscillator clock, carrying out zero clearing when an external microprocessor carries out read-write operation on the clock check timer, and generating an overflow interrupt signal when the counter is overflowed The overflow interrupt signal is used for controlling the register management logic module to stop transmit-receive operation to a CAN bus, counting serves as actual counting, the external microprocessor compares actual counting with expected counting, when the actual counting is inconsistent with the expected counting, the CAN bus controller is controlled to stop transmit-receive operation to the CAN bus.

Description

technical field [0001] The invention relates to the field of CAN bus control, in particular to a CAN bus controller. Background technique [0002] CAN is the abbreviation of Controller Area Network, which is an ISO international standardized serial communication protocol. At present, it is widely used in industrial automation, ships, medical equipment, industrial equipment and so on. The CAN bus controller is a circuit module used to implement the CAN bus protocol and interface with the microprocessor. The CAN bus works in a multi-master mode, and any node on the network can actively send information to other nodes on the network at any time, regardless of master-slave, and the communication method is flexible. The hardware composition of CAN nodes mainly includes CAN bus controller and transceiver, among which CAN bus controller can be divided into independent CAN bus controller and CAN bus controller integrated in CPU / MCU. [0003] The structure of the independent CAN b...

AI Technical Summary

Problems solved by technology

If the crystal oscillator clock "runs away" (usually multiplied), or the microprocessor fails, it may affect the paralysis of the entire CAN bus

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