CN209044584U

CN209044584U - CAN interface expanded circuit based on CPLD

Info

Publication number: CN209044584U
Application number: CN201821917569.4U
Authority: CN
Inventors: 黄祖钧
Original assignee: Shenzhen Yakeyuan Electric Co Ltd
Current assignee: Shenzhen Yakeyuan Electric Co Ltd
Priority date: 2018-11-21
Filing date: 2018-11-21
Publication date: 2019-06-28
Anticipated expiration: 2028-11-21

Abstract

The utility model discloses a kind of CAN interface expanded circuit based on CPLD, including CAN transceiver, CAN controller and CPLD module, the CAN transceiver and CAN controller electrical connection, the CAN controller is electrically connected with CPLD module, the CAN transceiver receives the data in CAN bus and is transmitted to CAN controller, the CAN controller receives data and is transmitted to CPLD module, data are transmitted to external MCU by dma bus by the CPLD module again, it receives the data of MCU simultaneously and is transmitted to CAN controller, data are transmitted to CAN transceiver by the CAN controller, the CAN transceiver again reaches data in CAN bus, the transmitting-receiving of the CAN controller data is controlled by CPLD module.CAN interface expanded circuit provided by the utility model based on CPLD, efficiency of transmission is high, it can be achieved that multichannel CAN interface extends.

Description

CAN interface expanded circuit based on CPLD

Technical field

The utility model relates to new energy battery testing fields, specifically, being related to a kind of CAN interface expansion based on CPLD Open up circuit.

Background technique

CPLD is a kind of user according to respective the need and voluntarily digital integrated electronic circuit of constitutive logic function.Its Basic Design Method is, with the methods of schematic diagram, hardware description language, to generate corresponding file destination by Integrated Development software platform, is led to It crosses download cable code is transmitted in objective chip, realizes the digital display circuit of design.

CAN bus occurs relatively early, is widely used in measurement, control and data by people and transmits.Extension CAN connects at present The mode of mouth is all IC2 ISP agreement, and such mode data transmission bauds is limited, and efficiency of transmission is not high.

Utility model content

The purpose of this utility model is to provide a kind of CAN interface expanded circuit based on CPLD, efficiency of transmission is high, can be real Existing multichannel CAN interface extension.

Technical solution used by CAN interface expanded circuit disclosed by the utility model based on CPLD is:

A kind of CAN interface expanded circuit based on CPLD, including CAN transceiver, CAN controller and CPLD module, it is described CAN transceiver and CAN controller electrical connection, the CAN controller are electrically connected with CPLD module, and the CAN transceiver receives CAN Data in bus are simultaneously transmitted to CAN controller, and the CAN controller receives data and is simultaneously transmitted to CPLD module, the CPLD module Data parallel is transmitted to external MCU again by dma bus, while CPLD receives the data of MCU parallel and is transmitted to CAN control Data are transmitted to CAN transceiver by device, the CAN controller, and the CAN transceiver again reaches data in CAN bus, described The transmitting-receiving of CAN controller data is controlled by CPLD module.

Preferably, one CPLD module at least controls two CAN controllers, the CPLD module and CAN It is parallel that the mode of data is transmitted between controller.

Preferably, the CAN transceiver is isolated transceiver.

Preferably, discharge tube and Transient Suppression Diode are parallel between the CAN bus differential signal.

Preferably, discharge tube and Transient Suppression Diode are in series between the CAN bus and ground.

The beneficial effect of CAN interface expanded circuit disclosed by the utility model based on CPLD is: CAN transceiver and The data transmission an of CAN interface may be implemented in one CAN controller.CPLD is used to control the data transmission of CAN controller, and The data received are passed through into dma bus again and are transmitted to external CPU parallel.And a CPLD can control multiple CAN controllers, It may be used for extension CAN interface.

Detailed description of the invention

Fig. 1 is the signal flow graph of CAN interface expanded circuit of the utility model based on CPLD.

Fig. 2 is the CAN transceiver circuit diagram of CAN interface expanded circuit of the utility model based on CPLD.

Fig. 3 is the CAN controller circuit diagram of CAN interface expanded circuit of the utility model based on CPLD.

Fig. 4 is the CPLD module circuit diagram of CAN interface expanded circuit of the utility model based on CPLD.

Specific embodiment

The utility model is further elaborated and is illustrated with Figure of description combined with specific embodiments below:

Please refer to Fig. 1, Fig. 2 and Fig. 3, a kind of CAN interface expanded circuit based on CPLD includes CAN transceiver, CAN control Device, CPLD module.CAN transceiver and the electrical connection of CAN controller module, CAN controller module are electrically connected with CPLD module.

CAN transceiver is the chip U30 of model ISO1050DUB.Chip U30 is a kind of isolated CAN transceiver, can be with It prevents external CAN interface power transmission abnormal, plays the role of the entire circuit of protection.CAN transceiver will receive the difference in CAN bus Signal, and differential signal is converted into serial data and is transmitted to CAN controller module again.CAN controller module is transmitted simultaneously Serial data, and convert serial data into differential signal and retransmit to CAN bus.Wherein, electric discharge is parallel between CAN bus Pipe and Transient Suppression Diode, are in series with discharge tube and Transient Suppression Diode between CAN bus and ground, be all to prevent surge electric Pressure, to play the role of protecting circuit.

CAN controller is model SJA1000T chip U27 and U28.The string that CAN controller transmits reception CAN transceiver Row data, and convert serial data into parallel data and be transmitted to CPLD module again.Receive what CPLD module transmitted simultaneously Parallel data, and convert parallel data into serial data and be transmitted to CAN transceiver again.CAN controller is electrically connected with crystal oscillator Y1, Crystal oscillator Y1 provides working frequency for CAN controller.

CPLD module includes CPLD chip, crystal oscillator Y3, debugging interface J4 and cpu peripheral interface P1.CPLD chip receives CAN The parallel data that controller transmits, and data parallel is transmitted on dma bus, dma bus tune is finally passed through by external MCU Use data.The data that MCU is transmitted are received simultaneously, and send data to corresponding CAN controller.Wherein, CPLD controls CAN control The data of device processed are transmitted, and can carry out caching process to data.CPLD chip is electrically connected with crystal oscillator Y3, and crystal oscillator Y3 is CPLD core Piece provides working frequency.Debugging interface is used to complete the debugging efforts of entire circuit.Cpu peripheral interface is used for cpu peripheral, should CPU need to have the function of dma bus.

In the present embodiment, CPLD chip model is XC95288XL-10TQ, but the model of CPLD chip has no effect on this The implementation of technical solution, CPLD chip can also be substituted with fpga chip.

Finally it should be noted that above embodiments are only to illustrate the technical solution of the utility model, rather than to this reality With the limitation of novel protected range, although being explained in detail referring to preferred embodiment to the utility model, this field it is general Lead to it will be appreciated by the skilled person that can be with the technical solution of the present invention is modified or equivalently replaced, without departing from this The spirit and scope of utility model technical solution.

Claims

1. a kind of CAN interface expanded circuit based on CPLD, which is characterized in that including CAN transceiver, CAN controller and CPLD Module, the CAN transceiver and CAN controller electrical connection, the CAN controller are electrically connected with CPLD module, the CAN transmitting-receiving Device receives the data in CAN bus and is transmitted to CAN controller, and the CAN controller receives data and is transmitted to CPLD module, described Data parallel is transmitted to external MCU by dma bus by CPLD module again, while CPLD receives the data of MCU parallel and is transmitted to Data are transmitted to CAN transceiver by CAN controller, the CAN controller, and data are reached CAN bus again by the CAN transceiver On, the transmitting-receiving of the CAN controller data is controlled by CPLD module.

2. the CAN interface expanded circuit based on CPLD as described in claim 1, which is characterized in that one CPLD module Two CAN controllers are at least controlled, it is parallel that the mode of data is transmitted between the CPLD module and CAN controller.

3. the CAN interface expanded circuit based on CPLD as described in claim 1, which is characterized in that the CAN transceiver be every From formula transceiver.

4. the CAN interface expanded circuit based on CPLD as described in claim 1, which is characterized in that the CAN bus difference letter Discharge tube and Transient Suppression Diode are parallel between number.

5. the CAN interface expanded circuit based on CPLD as described in claim 1, which is characterized in that the CAN bus and ground Between be in series with discharge tube and Transient Suppression Diode.