JPH06282458A - Method for communication between electronic control unit and monitor device - Google Patents

Abstract

PURPOSE:To lighten the load on the electronic control unit side by decreasing the frequency of sampling as much as possible while increasing monitor precision, and shortening a communication time. CONSTITUTION:While the electronic control unit(ECU) 1 and monitor device 2 handshake, the storage contents of the memory part 13 of the ECU 1 are monitored by the monitor device 2 in real time. Monitor channels are grouped according to the degree of changes of monitor elements and the sampling rate of a group is made higher and higher as the degree of changes of monitor elements is higher and higher. For example, the monitor channels are divided into three high-speed, intermediate-speed, and low-speed groups in the decreasing order of the sampling rates. The high-speed group includes monitor elements which require a process or interruption process at time intervals of <=5ms, the intermediate-speed group includes monitor elements which require a process at time intervals of 5-20ms, and the low-speed group includes monitor elements requiring a process at time intervals of >=20ms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of communication between an electronic control unit and a monitor device for monitoring the contents stored in its memory section.

[0002]

2. Description of the Related Art Generally, an electronic control unit (ECU) used for automobiles, home electric appliances and the like has a CPU and a ROM and a RAM as a memory section. When developing this ECU, it is necessary to rewrite the ROM contents (control data etc.) and monitor the RAM contents (temporarily used control variables etc.). In particular, in the case of an ECU used for automobile engine control, ABS control, etc., it is necessary to monitor in real time the correlation between the behavior of the automobile and the control program, and to make further studies, and a monitor device is used.

By the way, conventionally, a soft handshake method is known as a communication method between the ECU and the monitor device. In this system, the ECU is
The monitor address, which is the address value of the requested data, is sent to the ECU side, and the ECU side sends the requested address data (RA
M content) is transmitted. This exchange is performed for the number of monitor channels, and one sampling is completed. That is, there is a one-to-one relationship between the monitor address request and the data transmission for each monitor channel, and the monitor address request and the data are sent at the same time interval (sample upgrade) for all monitor channels. The transmission is repeated.

[0004]

However, in the above-described conventional soft handshake method, the monitor address request and the data transmission are performed with the same sample for all the monitor channels, although the degree of change of the monitor elements is different. Since communication is repeated, the communication time becomes longer accordingly. This communication becomes a load on the ECU side,
Since the original control cannot be performed during this communication time, there is a problem that a longer communication time leads to an increase in the load on the ECU side.

The present invention has been made in view of the above circumstances, and an object of the present invention is to change the sampling rate of each monitor channel in accordance with the degree of change of a monitor element to improve the monitoring accuracy and perform sampling. The number of times is reduced to shorten the communication time and reduce the load on the ECU side.

[0006]

In order to achieve the above object, the invention according to claim 1 uses a monitor channel as a communication method between an electronic control unit and a monitor device for monitoring the contents stored in its memory section. The monitor elements are divided into groups according to the degree of change of the monitor elements, and the higher the degree of change of the monitor elements, the higher the sampling rate of the group.

The invention according to claim 2 is dependent on the invention according to claim 1, and more specifically shows the grouping of monitor channels. That is, the monitor channel is divided into three groups of high speed, medium speed and low speed in the order of high sampling rate, and the high speed group has 5 m.
Monitor elements that require processing or interrupt processing at time intervals of s or less are included, the medium speed group includes monitor elements that need processing at time intervals within 5 to 20 ms, and the low speed group includes 20 ms. It is configured to include monitor elements that require processing at the above time intervals.

[0008]

With the above construction, in the invention according to claim 1,
When the development support device monitors the stored contents of the memory section of the electronic control unit while performing a handshake between the electronic control unit and the development support device, the monitor channels are grouped according to the degree of change of the monitor element, and the monitor element The higher the degree of change in the group, the higher the sampling rate of the group, so that the number of times of sampling or the number of times of communication can be reduced as much as possible without lowering the monitoring accuracy.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a communication device for using a communication method according to an embodiment of the present invention. This communication device serially transmits and receives signals between an electronic control unit (ECU) 1 and a monitor device 2. It is done by communication.

The ECU 1 includes a CPU 11, a ROM (read only memory) 12 as a memory unit, and an R.
An AM (random access memory) 13 and a serial communication unit 14 are built in. The CPU 11 is set to the extended bus mode, and the address bus 15, data bus 16 and control bus 17 are all in the ROM 1
2, RAM 13 and serial communication unit 14, respectively. The ROM 12 stores a control program for the ECU 1, control data, a RAM monitor program (a monitor service routine described later), and a serial communication program. The RAM 13 stores control variables that are temporarily used by the CPU 11 for control, and is used as a work area for calculation.

The serial communication section 14 is an interface section for carrying out serial communication with the monitor device 2 side, and the communication is carried out. The transmission converts each signal of command and data sent from CPU 11 via each bus 15 to 17 in parallel communication into serial communication,
Output to the monitor device 2 side. In addition, reception is performed by the monitor device 2
The data signal sent from the side by serial communication is received, converted into parallel communication, and sent to the CPU 11.

On the other hand, the monitor device 2 includes the ECU 1
Of the RAM 13 is monitored, and the control command unit 21, the RAM monitor control unit 22, the RAM monitor collection unit 23, the RAM monitor display unit 24, and the serial communication unit 2 are monitored.
5 and. RAM monitor controller 22 and RA
The M monitor collection unit 23 and the serial communication unit 25 are connected to each other via three types of buses, that is, an address bus 26, a data bus 27, and a control bus 28 so that signals can be exchanged between them.

The control command section 21 outputs a control command to the RAM monitor control section 22 in response to a request (including operation) from a user or the like. The RAM monitor controller 22
Receives a command from the control command unit 21, and receives the serial communication unit 2
5, RAM monitor collection unit 23 and RAM monitor display unit 2
4 is controlled. In addition, the RAM monitor collecting unit 23
Receives the control command of the RAM monitor control unit 22 and collects the RAM monitor data input from the serial communication unit 25 through the data bus 27. After that, the monitor data is sent to the RAM monitor control unit 22. The RAM monitor display unit 24 outputs the monitor data sent from the RAM monitor control unit 22 to the screen in real time.

Further, the serial communication section 25 is an EC
It is an interface part that performs serial communication with the U1 side, and the communication performs transmission / reception. For transmission, each signal of command and data sent from the RAM monitor control unit 22 in parallel communication is converted into serial communication and transferred to the serial communication unit 14 on the ECU 1 side. In addition, the reception is performed by receiving the data signal sent from the ECU 1 side through serial communication,
It is converted into parallel communication and sent to the RAM monitor collection unit 23.

The serial communication unit 14 on the ECU 1 side and the serial communication unit 25 on the monitor device 2 side are connected by a cable 31 so that they can be transmitted and received by serial communication, and both ends of the cable 31 are respectively connected to each other. It is connected to the connection connectors 14a and 25a of the serial communication units 14 and 25. Transmission and reception between the serial communication units 14 and 25 are performed while handshaking each other.

Next, a communication method between the ECU 1 and the monitor device 2 according to the present invention will be described with reference to the flowcharts shown in FIGS. 2 and 3 show a monitor routine which is a protocol (flow) on the monitor device side, and FIG. 4 shows a monitor service routine which is a protocol on the ECU side. Note that the communication is a common address called a device address (XX00 to XX02, X
X can be arbitrarily set), and communication is performed using this address as a window. Also, the flow is 1 when the CPU 11 has 8 bits.
In order to use the case of 6 bits, the reading and writing of signals are performed twice.

2 and 3, after the start,
First, in step S51, the monitor channels are divided into three groups of high speed, medium speed, and low speed. The high-speed greep includes a monitor element that has a high degree of change in the monitor element and requires processing or interrupt processing at a time interval of 5 ms or less. The medium speed group includes monitor elements that have a moderate degree of change in the monitor elements and that require processing at time intervals within 5 to 20 ms. The low speed group includes monitor elements that have a low degree of change in the monitor elements and that can be processed in a time interval of 20 ms or more. For example, in the case of an automobile engine control ECU, the engine speed, the intake flow rate, the ignition timing, etc. are included in the high speed group, and the elements operated by the driver such as the accelerator depression degree and the engine mode switching are included in the medium speed group, Intake gas temperature, water temperature, etc. are included in the low speed group. Then, the high speed group is set to the address table Tf and the medium speed group is set to the address table Tf.
The low speed group is set in m and the low speed group is set in the address table Ts.

Then, in step S52, the connection data 80h, which means the connection with the ECU 1, is set to the device address XX.
02, and sends it to the ECU 1 side, and then the step S
At 53, the previous sample flag Fo is read and the current sample flag F is set as follows. That is, if the previous sample flag Fo is high, the current sample flag F is set to medium speed, if the previous sample flag Fo is medium speed, the current sample flag F is set to low speed, and the previous sample flag Fo is low. For example, the sample flag F is set at high speed this time.

Then, in step S54, it is determined whether the current sample flag F is high speed, medium speed or low speed. If the sampling flag F is low this time, a value obtained by adding the number of monitor channels to each of the high-speed group, medium-speed group, and low-speed group is set in step S55, and the monitor address table T is set to the above three values in step S56. The value of each address table Tf, Tm, Ts of one group is set. If the sampling flag F this time is medium speed, a value obtained by adding the number of monitor channels to the number of each of the high speed group and the medium speed group is set in step S57, and in step S58, the above two groups are set in the monitor address table T. The values of the respective address tables Tf and Tm are set. Further, when the sampling flag F is high speed this time, the number of monitor channels is set to the value of the number of high speed groups only in step S59, and the value of the address table Tf of only high speed groups is set to the monitor address table T in step S60. To do.

Thereafter, in steps S61 and S62, the monitor address is written to the device address XX00 in two steps, that is, the upper address and the lower address, and the ECU 1
Send to the side. Then, in steps S63 and S64, the device address XX01 is read, monitor data sent from the ECU 1 side (two times of upper data and lower data) is obtained, and data is collected by the RAM monitor based on the data sending information. It is stored in the unit 23.

Subsequently, in step S65, it is determined whether or not the collection of the monitor data of all the channels is completed. If the determination is NO, in the step S66, the in-collection data which means that the monitor data of all the channels is being collected. After writing 01h to the device address XX02, the process proceeds to step S69. On the other hand, if the determination is YES, in step S67, the collection end data 00h, which means the end of the collection of the monitor data of all channels, is set to the device address XX.
After writing to 02, the current sample flag F is substituted for the previous sample flag Fo in step S68 to update the previous sample flag Fo, and the process proceeds to step S69. Then, in step S69, it is determined whether or not the command from the control command unit 21 is to end the monitoring. If the determination is NO, the process returns to step S52, while the determination is YES.
If, the control ends.

In FIG. 9, after starting, the device address XX02 is first read in step S71, and the device address XX02 is read in step S72.
It is determined whether the value of is the connection data 80h. When this determination is NO, the process returns without any operation, while
When the determination is YES, in steps S73 and S74, the device address XX00, which is the monitor address, is read in two times, the high-order address and the low-order address, and then, in steps S75 and S76, the RAM 13 corresponding to the monitor address is read. The contents (monitor data) are written to the device address XX01 in two times, the upper byte and the lower byte, and sent to the development support apparatus 2 side.

Then, in step S77, the device address XX02 is read again, and in step S78 it is determined whether or not the value of the device address XX02 is the collection end data 00h. If the determination is NO, the process returns to step S73, while if the determination is YES, the process returns.

ECU 1 based on such a protocol
In the case of communication between the development support device 2 and the development support device 2, the development support device 2 (RAM monitor control unit 22) divides the monitor channels into three groups of high speed, medium speed, and low speed in advance according to the degree of change of the monitor element. . Then, at the time of the first sampling, the monitor channels of all the groups of high speed, medium speed, and low speed are sent to the ECU 1 side as monitor address signals, and correspondingly, the monitor data for all the channels is sent from the ECU 1 side to the development support device 2 ( It is input to the RAM monitor collection unit 23). In addition, during the second sampling, the monitor channels of the high speed and medium speed groups are sent to the ECU 1 side as monitor address signals, and correspondingly, the monitor data for the number of monitor channels of the high speed and medium speed groups is supported from the ECU 1 side. Input to the device 2. At the time of the third sampling, only the monitor channel of the high speed group receives the ECU as the monitor address signal.
1 is sent to the development support device 2, and the monitor data corresponding to the number of monitor channels of the high speed group is input to the development support device 2 from the ECU 1 side. The above is repeated in the fourth and subsequent samplings. Therefore, the number of times the monitor data is sampled can be reduced as much as possible without lowering the monitor accuracy, and the communication time for monitoring can be shortened and the load on the ECU 1 side can be reduced.

In the above embodiment, the serial communication units 14 and 25 are provided in the ECU 1 and the monitor device 2, respectively, and the serial communication units 14 and 25 are connected via the cable 31 to perform serial communication. As mentioned above, the present invention is not limited to the case of this serial communication, and the EC
The same can be applied to the case of parallel communication in which communication between the ECU and the monitor device is performed using the CPU bus in the U.

In the above embodiment, the present invention is applied to the ECU.
1 has been described as applied to the communication method between the monitor 1 and the monitor device 2 for monitoring the contents stored in the RAM 13.
It goes without saying that the present invention can be similarly applied to the communication method between the ECU and the monitor device that monitors the storage contents of the ROM.

[0028]

As described above, according to the communication method of the present invention, when the stored contents of the memory section of the electronic control unit are monitored by the monitor device while performing the handshake between the electronic control unit and the monitor device, The channels are divided into groups according to the degree of change of the monitor element, and the higher the degree of change of the monitor element, the higher the sampling rate of that group. Therefore, the communication time can be shortened and the load on the electronic control unit can be reduced accordingly.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a communication device for using a communication method according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a monitor routine.

FIG. 3 is a flowchart of the same.

FIG. 4 is a flowchart showing a monitor service routine.

[Explanation of symbols]

 1 electronic control unit (ECU) 2 monitor device 13 RAM (memory section)

Claims (2)

[Claims] 1. A communication method between an electronic control unit and a monitor device for monitoring the stored contents of a memory section thereof, wherein monitor channels are grouped according to the degree of change of the monitor element, A method of communication between an electronic control unit and a development support device, characterized in that the higher the degree of change, the higher the sampling rate of the group. 2. The monitor channel is divided into three groups of high speed, medium speed and low speed in the order of higher sampling rate, and the high speed group includes monitor elements that require processing at time intervals of 5 ms or less or interrupt processing. The middle speed group includes monitor elements that require processing at a time interval of 5 to 20 ms, and the low speed group includes 20 m.
The communication method between the electronic control unit and the development support apparatus according to claim 1, further comprising a monitor element that requires processing at a time interval of s or more.