CN1580987A

CN1580987A - Method for electronic control unit for expanding single CAN bus module into double CAN

Info

Publication number: CN1580987A
Application number: CNA2004100379616A
Authority: CN
Inventors: 刘原; 许家群; 陈林; 李建秋
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2004-05-17
Filing date: 2004-05-17
Publication date: 2005-02-16
Anticipated expiration: 2024-05-17
Also published as: CN1279410C

Abstract

The present invention discloses an electronic control unit method is used in industrial site control with requirement for CAN bus,in particulr is applicable to car site control having CAN bridge requirement and capable of expanding single CAN bus modules into double CAN. Said method is characterized by that the data bus, address bus and control buss of Motorola 68MC376 chip microprocessor and Intel 82527 CAN controller chip are correspondently connected, two groups of CAN signals are connected into CAN transceiver by means of photoelectric isolation to implement exterior connection of CAN bus, then the software and hardware configuration can be used to map Intel 82527 CAN into the addressing space of motorola 68 MC 376 chip microprocessor so as to implement expansion of CAN module based on Motorola 68 MC 376.

Description

A kind of method that single CAN bus module is extended to the electronic control unit of two CAN

Technical field

The invention belongs to the electron controls technology field, be particularly related to the industry spot control that is used for the CAN bus is had requirement, be particularly useful for having a kind of method that single CAN bus module is extended to the electronic control unit of two CAN of the automobile-used field control of CAN bridge requirement.

Background technology

Controller local bus (CAN) has been the bussing technique of modern industry field control institute widespread use.In the part commercial Application, can occur an electronic control unit (ECU) usually and be operated in two situations in the CAN network simultaneously.In this case, ECU plays the effect of the bridge of master controller and CAN network.

In the low side CAN network controller commonly used at present, generally cooperate SJA1000 to carry out the CAN Module Design with 51 series monolithics.Because 51 single-chip microcomputers do not have advantage on arithmetic capability and peripheral modules, this design can not be satisfied the application requirements that some real-times require high, that data throughput is big, the computing demand is many most automobile-used controls.

Motorola 68MC376 is a 32 powerful single-chip microcomputers of motorola inc, has powerful operation capacity and abundant peripheral modules resource, is fit to most vehicle-mounted control and uses.Yet this single-chip microcomputer itself only has a CAN control module (TouCAN), be operated in two or more CAN networks, also needs its external module is carried out a series of expansion.

Summary of the invention

The purpose of this invention is to provide a kind of method that single CAN bus module is extended to the electronic control unit of two CAN.

Technical scheme of the present invention is that the present situation that can not directly apply in two or more CAN networks with Motorola 68MC376 single-chip microcomputer is an example, expand accordingly by outside this single-chip microcomputer, and by rational software and hardware configuration, it is easy-to-use to make external CAN module equally with built-in CAN module to stablize, and is the ability to work of ECU in a plurality of CAN networks of core thereby widened with Motorola 68MC376 single-chip microcomputer.It is characterized in that: with corresponding connection of address bus, data bus and control bus of address bus, data bus and control bus with the Motorola 68MC376 single-chip microcomputer of Intel82527 chip, again by corresponding software and hardware configuration, the CAN module that Intel.82527 forms is mapped to the addressing space of Motorola 68MC376 single-chip microcomputer, thereby realize Motorola 68MC376 single-chip microcomputer circumferential expansion being become to contain the electronic control unit of two CAN, and realize the configuration of automatic interrupt vector.Concrete grammar is: establishing U1 earlier is the Motorola68MC376 single-chip microcomputer, if U17 is Intel 82527 CAN controllers, the annexation of the two is as follows: the respective pins calculated address bus that A0～A7 of U1 is directly connected to U17 connects, and the respective pins that D8～D15 of U1 is directly connected to U17 forms the data bus connection.Control bus comprises the R/W read-write, chip selection signal CS4, and data answering signal DSACK0, interrupt configuration signal INT and reset signal PE7, wherein the INT signal is implemented in the flexible selection between IRQ4 or the IRQ5 by three end wire jumper Jumper2 or Jumper3; Socket high level on the INT signal, the AVEC of U1 is by the drop-down ground connection of resistance, and DSACK1 is by socketing high level on the resistance.The CANTX0 of U1 and CANRX0 constitute the original signal of CANA, and U17 is by the original signal of RCAN, the TCAN formation CANB of wire jumper output, and the CAN light that is connected to standard forms CANA and CANB two-way CAN signal in output circuit.Wherein light every back level be the power supply that forms by insulating power supply, thereby the electromagnetic performance of assurance CAN network.

The invention has the beneficial effects as follows the expansion that has realized based on the CAN module of Motorola 68MC376.Be applicable to the industry spot control that the CAN bus is had requirement, be particularly useful for having the automobile-used field control of CAN bridge requirement.This method is applicable to that also Motorola 68K and even PowerPC 500 series monolithics further expand, and realizes the more CAN expansion of multichannel.

Description of drawings

Fig. 1 is the method block diagram that single CAN bus module is extended to the electronic control unit of two CAN.

Fig. 2 is the hardware configuration synoptic diagram that contains the Intel82527 chip.

Embodiment:

Figure 1 shows that single CAN bus module is extended to the method block diagram of the electronic control unit of two CAN.This method is corresponding connection of data bus, address bus and control bus with Motorola 68MC376 single-chip microcomputer and Intel 82527 CAN controller chips, two groups of CAN signals are connected in the CAN transceiver by the photoelectricity isolation, the outside of realizing the CAN bus connects, by software and hardware configuration, Intel 82527 CAN are mapped in the addressing space of Motorola 68MC376 single-chip microcomputer again.

Figure 2 shows that the hardware configuration synoptic diagram that contains the Intel82527 chip.U1 is the Motorola68MC376 single-chip microcomputer among the figure, U17 is Intel 82527 CAN controllers, the annexation of the two is as follows: the respective pins calculated address bus that A0～A7 of U1 is directly connected to U17 connects, and the respective pins that D8～D15 of U1 is directly connected to U17 forms the data bus connection.Control bus comprises the R/W read-write, chip selection signal CS4, data answering signal DSACK0, interrupt configuration signal INT, signals such as reset signal PE7.Wherein the INT signal passes through one three end wire jumper in being connected to the process of U1, in order to be implemented in the flexible selection between IRQ4 or the IRQ5.Socket high level on the INT signal demand.The AVEC of U1 need pass through the drop-down ground connection of resistance in addition, and DSACK1 need be by socketing high level on the resistance.

Need partly realizing being connected of crystal oscillator and support circuit of U17 part according to illustrating.Jumper2 and Jumper3 are three end wire jumpers, are connected respectively to RX0, RX1 and TX0, TX1, in order to select the dominance output level of bus signals.

The CANTX0 of U1 and CANRX0 constitute the original signal of CANA, and U17 is by the original signal of RCAN, the TCAN formation CANB of wire jumper output, and the CAN light that is connected to standard forms CANA and CANB two-way CAN signal in output circuit.Wherein light every back level be the power supply that forms by insulating power supply, thereby the electromagnetic performance of assurance CAN network.

The software and hardware configuration of this method is as follows:

Table 1: wire jumper allocation list

Wire jumper	The 1-3 short circuit	The 2-3 short circuit	Default setting	Remarks
Wire jumper	The 1-3 short circuit	The 2-3 short circuit	Default setting	Remarks	??Jumper1	Use IRQ5	Use IRQ4	The 1-3 short circuit	Be used to select the interrupt source of 68MC376
??Jumper2	Use RX0, TX0	Use RX1, TX1	The 1-3 short circuit	82527 CAN signal shows recessive configuration	??Jumper1	Use IRQ5	Use IRQ4	The 1-3 short circuit	Be used to select the interrupt source of 68MC376
??Jumper2					??Jumper3

In default setting, it is as follows to carry out corresponding configuration with software to 82527:

MOVE.L??#0x12007BFB，0xFFFFFA5C；??……………………………………1*

MOVE.B??#0x20，0xFFFFFA1F；????????……………………………………2*

MOVE.B??#0x07，0xFFFFFA17；????????……………………………………3*

1* is used to dispose sheet and selects CS4, promptly finishes 82527 the physical address and the configuration of use-pattern.This is provided with and is configured on the base address of 0x120000 82527, and its corresponding D SACK is configured to outside access way.In addition, this order has stipulated that also this sheet choosing is operated in the readable pattern of writing of high low level.Because the address of 82527 inside is 0x00～0xFF, so during actual program, 82527 addressing spaces that are mapped in 68MC376 are 0x120000～0x1200FF.

2* is used for the pin assignments of the port F of regulation 68MC376.Because IRQ5 is used as interrupt source, so corresponding PF5 should set be high, the interrupt vector of correspondence number is 29.

3* is high with the low position, three positions of port E, and low three pins that are used to specify port E are respectively applied for DSACK0, DSACK1 and AVEC.

Because the PE7 signal with 68MC376 in the hardware design has been connected to 82527 reset signal, so in use can realize to 82527 reset to most significant digit (PE7) the low level output of port E.Should be set to high level by PE7 in the normal use.

Owing to adopted such expansion, all be assigned to 82527 internal register from the address of 0x120000～0x1200ff.In actual use, only need carry out corresponding read-write operation to this sector address, just finish operation 82527 CAN modules with software.Concrete software operation is as CAN initialization, CAN information object initialization operation.The method of actual transmission and reception CAN information is referring to the device handbook of Intel 82527.Based on the addressing of 68MCC376 and other read-write operations referring to Motorola 68MC376 user manual.

So far, the Intel82527CAN module after the TouCAN module of 68MC376 inside and the expansion has constituted two CAN modules, thereby ECU can be operated in two CAN networks, realizes the function of bridge.

Claims

1. method that single CAN bus module is extended to the electronic control unit of two CAN, this method is that the present situation that can not directly apply in two or more CAN networks with Motorola 68MC376 single-chip microcomputer is an example, expand accordingly by outside this single-chip microcomputer, it is characterized in that: with the address bus of Intel82527 chip, the address bus of data bus and control bus and Motorola 68MC376 single-chip microcomputer, data bus is connected with control bus is corresponding, again by corresponding software and hardware configuration, the CAN module that Intel.82527 forms is mapped to the addressing space of Motorola 68MC376 single-chip microcomputer, thereby realize Motorola 68MC376 single-chip microcomputer circumferential expansion being become to contain the electronic control unit of two CAN, and realize the configuration of automatic interrupt vector; Concrete grammar is: establishing U1 earlier is Motorola 68MC376 single-chip microcomputer, if U17 is Intel 82527 CAN controllers, A0～A7 of U1 is directly connected to the respective pins calculated address bus connection of U17, the respective pins that D8～D15 of U1 is directly connected to U17 forms the data bus connection, control bus comprises the R/W read-write, chip selection signal CS4, data answering signal DSACK0, interrupt configuration signal INT and reset signal PE7, wherein the INT signal is implemented in the flexible selection between IRQ4 or the IRQ5 by three end wire jumper Jumper2 or Jumper3; Socket high level on the INT signal, the AVEC of U1 is by the drop-down ground connection of resistance, and DSACK1 is by socketing high level on the resistance; The CANTX0 of U1 and CANRX0 constitute the original signal of CANA; U17 is by the original signal of RCAN, the TCAN formation CANB of wire jumper output, and the CAN light that is connected to standard forms CANA and CANB two-way CAN signal in output circuit; Wherein light every back level be the power supply that forms by insulating power supply, thereby the electromagnetic performance of assurance CAN network.