CN106533873A

CN106533873A - CAN bus node chip including transceiver and controller

Info

Publication number: CN106533873A
Application number: CN201611027091.3A
Authority: CN
Inventors: 赵毅强; 解啸天; 束庆冉; 朱世贤
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2016-11-15
Filing date: 2016-11-15
Publication date: 2017-03-22
Anticipated expiration: 2036-11-15
Also published as: CN106533873B

Abstract

The invention belongs to the field of CAN onsite buses. A CAN bus transceiver and a CAN bus controller are integrated in the same chip, the chip is miniaturized, use of the CAN bus chip is simplified, and the integrated degree and the reliability of a CAN onsite bus system are improved. A CAN bus node chip including the transceiver and the controller is composed of a bus transceiver module and a CAN bus controller module; the CAN bus controller module is composed of an internal dwell vessel, an interface management logic unit, a bit flow processor, an acceptance filter, a bit time sequence logic unit and a data buffer; the bus transceiver module comprises a sending part and a reception part; the sending part is composed of two driving control modules a NOT gate, two switch MOS tubes and a divider resistor; and the reception part is formed by a retardation comparator. The CAN bus node chip including the transceiver and the controller is mainly applied to design and manufacture occasions of a CAN onsite bus device.

Description

CAN node chip comprising transceiver Yu controller

Technical field

The present invention relates to CAN fieldbus field, and in particular to a kind of total with the CAN of CAN transceiver comprising CAN controller Line node chip, effectively increases the integrated level and reliability of CAN system.

Background technology

With the development of computer networking technology and chip technology, in network system, the performance of control chip is greatly improved, Cost is constantly reduced, the controlling network with fieldbus as representative also industry and other control system in play it is indispensable Few role.Fieldbus realizes the number of two-way, serial, multi-point between measurement control device using at the scene Word communication system.It inserts traditional measuring and controlling instrument table general or special microprocessor, is allowed to numerical calculation And digital communicating ability.Which adopts certain medium as communication bus, according to the communication protocol of open, specification, positioned at existing Between the multiple equipment of field and between field apparatus and remote monitoring computer, realize that data transfer and information are exchanged, formed The various automation control systems for adapting to be actually needed.

CAN is the abbreviation of controlling network Control Area Network, and CAN fieldbus is based on CAN protocol Plant fieldbus.CAN fieldbus has high traffic rate, direct long transmission distance, strong antijamming capability, can almost detect The series of advantages such as any mistake for occurring.The high-performance and reliability of CAN is accepted, and is widely used in industry certainly The aspects such as dynamicization, ship, armarium, industrial equipment.CAN is one of focus of nowadays automatic art, It is described as the LAN of automatic field.It appear as dcs realize between each node in real time, can The data communication leaned on provides strong technical support.

In CAN system, in a bus, generally connect multiple CAN nodes, each node all can basis in network Bus access prioritized contention sends to bus and can receive identical number of buses simultaneously between data, and different nodes According to.Each CAN node in system includes CAN transceiver and CAN controller, and the function of CAN transceiver is to realize that numeral is patrolled Collect the conversion between level and analog differential level.In CAN nodes, the internal signal of controller is digital logic level, and Signal in bus is analog differential level, and the effect of transceiver is exactly to realize the level conversion between controller and bus.CAN Controller is its key component, for a series of logic work(such as transmission and reception, troubleshooting, arbitration of control data Can, the perfect communication protocol that CAN has is realized by controller.

In actual CAN system, need CAN transceiver to cooperate with CAN controller, could realize multiple existing Data communication between field device and field apparatus and remote computer.But current CAN transceiver and CAN controller on the market Mostly discrete design, is not integrated to together, and this just brings inconvenience for the use of chip.

List of references

1、Dong-Hee Noh,Dong-Seong Kim.Message Scheduling on CAN Bus for Large-Scaled Ship Engine Systems[J].World Congress,2014,47(3):7911-7916.

2nd, Rao Yuntao, Zou Jijun, Zheng Yongyun. CAN Bus principle and application technology [M]. Beijing:Beijing Aviation space flight University press, 2007,12-18.

3rd, the clear people are carried out. teach by doing you and learn CAN [M]. Beijing:Publishing house of BJ University of Aeronautics ＆ Astronautics, 2010,109- 112。

The content of the invention

To overcome the deficiencies in the prior art, it is contemplated that CAN transceiver and CAN controller are integrated to together The Miniaturization Design of chip in one chip, is realized, simplifies the use of CAN chip, improve the integrated of CAN field bus systems Degree and reliability.The technical solution used in the present invention is, the CAN node chip comprising transceiver Yu controller, by bus Transceiver module, CAN controller module composition, CAN controller module by internal register, interface management logic, Bit stream processor, acceptance fitration, bit timing logic and data buffer composition, internal register are used to set various controls Signal, state between microcontroller and bus control unit, control and the exchange of command signal are all internally to complete in depositor； Interface management logic is used for the order for performing microcontroller, manages the addressing inside bus control unit.Bit stream processor is used for controlling Data flow between data buffer processed and CAN performs error detection simultaneously；During acceptance fitration is used to recognize CAN network Frame identification；Bit timing logic is responsible for processing the bit timing related to bus；The function of data buffer is the letter of storage transmitting-receiving Breath, which is divided into transmission buffer and receives buffer；

Bus transceiver module includes two parts, is transmitting portion and receiving portion respectively；Transmitting portion is driven by two Dynamic control module, not gate, two switch metal-oxide-semiconductors, divider resistance compositions, one drive control module of information access of transmission are sent out The information sent is while also access another drive control module by not gate, the output of two drive control modules is corresponded to respectively and connected The grid of a switch metal-oxide-semiconductor is connect so that difference output is formed to CAN；Receiving portion is made up of hysteresis comparator.

Drive control module is made up of phase inverter cascade.

The characteristics of of the invention and beneficial effect are：

The application of fieldbus is quite varied at present, and CAN has been applied to industry because of a series of its advantage The multiple fields such as automatization, ship, auto industry.Traditional CAN chip mostly is discrete design, and controller is with transceiver not Integrate, increased the use difficulty of chip, reduce the stability of CAN system.The present invention is by by CAN controls Device is integrated to same chip with CAN transceiver, realizes the Miniaturization Design of chip, simplifies the use of CAN chip, carry The high stability of CAN system.

Description of the drawings：

Fig. 1 CAN node chip overall structure block diagrams.

Fig. 2 transceiver module structural representations.

Fig. 3 entirety domains.

Fig. 4 CAN system schematics.

Specific embodiment

The present invention gives it is a kind of by CAN transceiver be integrated to CAN controller together with CAN node chip.

CAN transceiver and CAN controller are integrated to same chip by the present invention, and chip overall structure block diagram is as shown in Figure 1. Two modules of bus reception/sending module and bus protocol controller can be divided into.Transceiver module includes transmitting portion and connects Receiving portions, controller module include the functional modules such as internal register, to realize bus protocol.

CAN transceiver module structural representation is as shown in Fig. 2 mainly include transmitting portion and receiving portion.Send Part is made up of drive control module, switch metal-oxide-semiconductor, divider resistance, and receiving portion is then a hysteresis comparator.Resistance in figure R5 is bus equivalent resistance (generally 60 Ω), and to ensure the driving force to bus in actual design, during design, R5 is set to 50 ohm, R1 and R2 partial pressures obtain 2.5V voltages for providing the recessive biasing of bus, R3 and R4 be used to isolating dominant level and Recessive level (P0 and N0 are in the conduction state), diode are used to prevent level in bus too high or too low cause shadow to power supply Ring.When P0 and N0 is simultaneously turned on, the level of CANH and CANL is respectively 3.5V, 1.5V, and now the electric current in bus is 40mA, because Electric current when this P0 and N0 is turned on is 40mA, so needs the breadth length ratio larger (providing the electric current of 40mA) of P0 and N0.Vast scale Metal-oxide-semiconductor needs previous stage to have stronger driving force, so the drive circuit of phase inverter cascade is employed in circuit.Receiving circuit It is a hysteresis comparator, differential analog signal is converted into into digital signal, is for anti-stop signal using sluggish purpose Shake, improves the quality of signal.

Transceiver is the interface of data exchange, connects CAN controller and physical bus respectively, and essence is exactly to realize that bus is poor Galvanic electricity puts down the conversion to digital logic level.Accordingly, as a transceiver, I/O port is provided with the CANH of connection physical bus With CANL ports, and have from protocol controller end receive and send data RX and TX ports, and VDD and GND connect power supply and Grounding ports.

CANH correspondence high level buses, CANL correspondence low level buses, both are connected on physical bus, are received from total Differential wave on line.TX ports refer to data that Jing protocol controllers processed by this port be passed to transceiver then by Transceiver is sent in bus, referred to as sends FPDP；RX ports refer to that transceiver will receive differential number from physical bus According to protocol controller, referred to as receiving data port are transferred to after being processed as the digital signal of serial.

When CAN controller to transmitting terminal send digital logic level 0 when, obtain on physical bus differential level CANH and CANL is respectively 3.5V and 1.5V, and receiving terminal obtains signal 0；When CAN controller sends digital logic level 1 to transmitting terminal, Differential level CANH and CANL are obtained on physical bus and is respectively 2.5V and 2.5V, receiving terminal obtains signal 1.

CAN controller module is to realize the main modular of bus protocol, and which is divided into internal register, interface management Logic, bit stream processor, acceptance fitration, bit timing logic and data buffer.Internal register is used to set various controls Signal processed, state between microcontroller and bus control unit, control and the exchange of command signal are all complete in depositor internally Into.Interface management logic is used for the order for performing microcontroller, manages the addressing inside bus control unit.Bit stream processor is used for Data flow between control data buffer and CAN performs the functions such as error detection simultaneously.Acceptance fitration is used to recognize Frame identification in CAN network.Bit timing logic is responsible for processing the bit timing related to bus.The function of data buffer is storage The information of transmitting-receiving, which is divided into transmission buffer and receives buffer.

After design of the controller module with transceiver module is completed, by rational laying out pattern (as shown in Figure 3) Two modules are integrated in same chip.Through appropriate encapsulation, obtain being integrated with the CAN of CAN controller and CAN transceiver Bus node chip.

An example of the present invention is as follows：

Integrated testability is carried out to CAN node chip first, chip functions correctness is determined.With CAN node core Based on piece, CAN system is built.As shown in figure 4, each CAN node is by sensor and actor, microcontroller (monolithic Machine), CAN node chip composition, by appropriate sensor detect field apparatus generation change, executor send phase The signal answered controls CAN node chip and produces corresponding signal to microcontroller, then, and sends to total through arbitration Line, signal are sent to remote control computer by bus, and then make remotely control computer learn the change that field apparatus occurs Change, and respond.

Claims

1. a kind of CAN node chip comprising transceiver Yu controller, is characterized in that, total by bus transceiver module, CAN Lane controller module is constituted, and CAN controller module is by internal register, interface management logic, bit stream processor, examination filter Ripple device, bit timing logic and data buffer composition, internal register are used to set various control signals, microcontroller and total State between lane controller, control and the exchange of command signal are all internally to complete in depositor；Interface management logic is used for The order of microcontroller is performed, the addressing inside bus control unit is managed.Bit stream processor is used for control data buffer and CAN Data flow between bus performs error detection simultaneously；Acceptance fitration is used to recognize the frame identification in CAN network；Bit timing is patrolled Collect and be responsible for processing the bit timing related to bus；The function of data buffer is the information of storage transmitting-receiving, and it is slow which is divided into transmission Rush device and receive buffer；

Bus transceiver module includes two parts, is transmitting portion and receiving portion respectively；Transmitting portion is driven by two and is controlled Molding block, not gate, two switch metal-oxide-semiconductors, divider resistance compositions, one drive control module of information access of transmission, transmission Information also accesses another drive control module by not gate simultaneously, and the output of two drive control modules is connected respectively one The grid of individual switch metal-oxide-semiconductor is so as to forming difference output to CAN；Receiving portion is made up of hysteresis comparator.

2. the CAN node chip comprising transceiver with controller as claimed in claim 1, is characterized in that, drive control Module is made up of phase inverter cascade.