Primary Check System

Abstract

To reduce the number of output ports occupied for output when a plurality of output signals are output from a microcomputer.SOLUTION: A primary check system includes: a control unit configured to output data for primary check to a plurality of primary check circuits as a serial signal via a serial communication line; and a serial / parallel conversion circuit configured to convert the data for primary check received as the serial signal into a parallel signal and transmit the parallel signal to the plurality of primary check circuits. The control unit is configured to bring the serial / parallel conversion circuit into an active state before a primary check is started, and bring the serial / parallel conversion circuit into an inactive state when the primary check is completed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a primary check system.

Background Art

[0002] There is a system in which a plurality of primary check circuits are connected to a microcomputer, a signal including data for primary check is transmitted to each primary check circuit, and the primary check of a safety circuit is performed. In this case, each time the number of primary check circuits increases, the number of ports (terminals) of the microcomputer increases.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in a microcomputer used in an in-vehicle device, the number of signals to be output tends to increase with the multifunctionalization of the device. However, there is a problem that the number of output ports of the microcomputer is limited and not all required signals can be output.

[0005] An object of the present invention is to provide a technology capable of suppressing the number of output ports occupied for output when a plurality of output signals are output from a microcomputer.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention employs the following means. That is, the first aspect is A control unit that outputs data for primary check for a plurality of primary check circuits as a serial signal via a serial communication line, A serial / parallel conversion circuit that converts the data for primary check received by the serial signal into a parallel signal and transmits it to a plurality of primary check circuits, Before the start of the primary check, the control unit activates the serial / parallel conversion circuit, and when the primary check is completed, the control unit deactivates the serial / parallel conversion circuit. A primary check system.

Advantages of the Invention

[0007] According to the present invention, when a plurality of output signals are output from a microcomputer, it is possible to provide a technology that can suppress the number of output ports occupied for output.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configurations of the following embodiments are examples, and the present invention is not limited to the configurations of the embodiments.

[0010] 〔Embodiment〕 (Example of Configuration) FIG. 1 is a diagram showing an example of the configuration of the primary check system 10. The primary check system 10 of the present embodiment includes a microcomputer 100 and a serial-parallel IC 200 connected to the microcomputer 100. A plurality of primary check circuits 300A, 300B, 300C are connected to the serial-parallel IC 200. The primary check circuits 300A, 300B, 300C are collectively referred to simply as the primary check circuit 300. Safety circuits 400A, 400B, 400C are connected to each of the primary check circuits 300. The safety circuits 400A, 400B, 400C are collectively referred to simply as the safety circuit 400. The primary check system 10 may include the primary check circuit 300 and the safety circuit 400. Here, the number of the primary check circuit 300 and the safety circuit 400 is three each, but is not limited to three. The primary check system 10 may be provided with a power supply, or may be configured to receive power supply from an external power supply. The primary check system 10 of the present embodiment is used, for example, in an in-vehicle device mounted on a vehicle, is connected to an ECU (Electronic Control Unit), and receives power supply from the vehicle battery. Pr The primary check system 10 is not limited to being used in an in-vehicle device. The primary check system 10 is a system that performs a primary check, which is an operation check of the safety circuit 400 before the safety circuit 400 normally operates.

[0011] 〈Microcomputer〉 The microcomputer 100 includes a control unit 101, an output port 102, a serial communication circuit 103, and an input port 104. The microcomputer 100 is, for example, a so-called one-chip microcomputer in which these configurations are provided in one IC.

[0012] The control unit 101 includes a processor and a memory, and comprehensively executes various arithmetic processes in the microcomputer 100. The processor is an arithmetic processing means such as, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or an FPGA (Field-Programmable Gate Array). The memory is a storage means such as, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory), and is used as a main storage unit or an auxiliary storage unit.

[0013] The output port 102 is connected to the serial-parallel IC 200 and is a port for outputting a signal to the serial-parallel IC 200. The output port 102 transmits an enable signal for activating the serial-parallel IC 200 to the serial-parallel IC 200.

[0014] The serial communication circuit 103 performs serial communication with the serial communication circuit 202 of the serial-parallel IC 200. The serial communication circuit 103 is connected to the serial communication circuit 202 of the serial-parallel IC 200. The serial communication circuit 103 includes a receiving circuit for receiving an input signal from the serial-parallel IC 200 and a transmitting circuit for transmitting a signal to the serial-parallel IC 200.

[0015] The input port 104 is connected to each safety circuit 400 and is a port for receiving a signal from each safety circuit 400.

[0016] 〈Serial-Parallel IC〉 The serial-parallel IC 200 includes a control circuit 201, a serial communication circuit 202, and an output circuit 203. The serial-parallel IC 200 is an example of a serial / parallel conversion circuit.

[0017] The control circuit 201 comprehensively executes various arithmetic processes in the serial-parallel IC 200. The control circuit 201 receives an enable signal from the microcomputer 100 to activate the serial-parallel IC 200. While receiving the enable signal, the control circuit 201 activates the serial-parallel IC.

[0018] The control circuit 201 converts the serial signal received by the serial communication circuit 202 into a parallel signal. Based on predetermined settings, the control circuit 201 converts the serial signal into a signal for each primary check circuit 300 (parallel signal) and outputs it from the output circuit 203 to each primary check circuit 300.

[0019] The serial communication circuit 202 performs serial communication with the serial communication circuit 103 of the microcomputer 100.

[0020] The output circuit 203 is connected to each primary check circuit 300. The output circuit 203 outputs the signal converted from the serial signal to each primary check circuit 300. A plurality of signal lines may be provided between the output circuit 203 and one primary check circuit 300.

[0021] In the example of FIG. 1, two communication lines are used for serial communication between the microcomputer 100 and the serial-parallel IC 200, but the configuration is not limited thereto. Also, each communication line can be connected to other IC chips 500, etc. Each communication line has a branch line that branches to an IC chip 500, etc. in the middle. Each communication line and each branch line can be used as a communication line between the microcomputer 100 and the IC chip 500, etc. when the serial-parallel IC 200 is in an inactive state. That is, each communication line and each branch line can be used as a communication line between the microcomputer 100 and the IC chip 500, etc. after the primary check is completed. Each communication line is an example of a serial communication line. Each branch line is an example of a branch line. The IC chip 500 is an example of another circuit.

[0022] <Primary Check Circuit> When the safety circuit 400 is activated, the primary check circuit 300 transmits a test signal for primary check. The primary check circuit 300 receives the activation signal from the microcomputer 100 via the serial-parallel IC 200, starts operating when it receives the activation signal, and transmits a test signal to the safety circuit 400. The activation signal is data in a predetermined format, such as "1" if it is a 1-bit signal or "101" if it is a 3-bit signal. A plurality of signal lines are provided between the serial-parallel IC 200 and one primary check circuit 300, and the primary check circuit 300 may receive a plurality of activation signals. The primary check circuit 300 transmits a test signal to the safety circuit 400 based on the received activation signal. Signal lines can be provided between the primary check circuit 300 and the safety circuit 400 for each check item by the primary check circuit 300. One test signal corresponds to, for example, one check item.

[0023] <Safety Circuit> The safety circuit 400 is a circuit that detects abnormalities in components inside the vehicle, etc. The safety circuit 400 is, for example, a circuit connected to the vehicle battery to detect abnormalities in the vehicle battery (such as temperature rise, voltage drop, etc.). Also, the safety circuit 400 performs an inspection on whether the safety circuit 400 operates normally when the vehicle is started, etc., based on the test signal from the primary check circuit 300. The test signal from the primary check circuit 300 is, for example, a signal indicating an abnormality (a signal simulating an abnormality). In the inspection, When a test signal indicating an abnormality is input to the safety circuit 400, it is inspected whether the safety circuit 400 operates normally. The safety circuit 400 outputs the inspection result (operation result) of this inspection to the microcomputer 100. The inspection result includes analog signals and digital signals. The microcomputer 100 can determine whether the safety circuit 400 is operating normally based on the inspection result.

[0024] (Operation example) Figure 2 is a time chart showing the timings of the enable signal, serial communication, and output signal in the primary check system 10. In Figure 2, the horizontal axis indicates the passage of time. In Figure 2, time T1 is the time when the primary check system 10 is powered on. Time T1 is before the start of the primary check. For example, when an in-vehicle device equipped with the primary check system 10 is mounted on a vehicle, the timing at which the vehicle starts and the power of the in-vehicle device is turned on by turning on an ignition switch (not shown) is T1. At the time of power-on, the control unit 101 of the microcomputer 100 transmits an enable signal to the serial parallel IC 200 via the output port 102. The enable signal is, for example, a Hi signal among Hi and Lo. The control circuit 201 of the serial parallel IC 200 activates the serial parallel IC 200 while receiving the enable signal (Hi signal). The control unit 101 of the microcomputer 100 continues to transmit a Hi signal from the time of power-on until the primary check is completed (from T1 to T3). Also, the control circuit 201 of the serial parallel IC 200 deactivates the serial parallel IC 200 while receiving a Lo signal (not receiving a Hi signal). When the serial parallel IC 200 is in an active state, the serial parallel IC 200 can operate. After the serial parallel IC 200 becomes active, the microcomputer 100 and the serial parallel IC 200 perform initial settings (register settings). The control unit 101 of the microcomputer 100 sets, as initial settings, setting information such as which primary check circuit 300 (which safety circuit 400) among a plurality of primary check circuits 300 (a plurality of safety circuits 400) to transmit a signal to in the case of what serial signal to the serial parallel IC 200. The signal for the initial settings (register settings) is transmitted from the serial communication circuit 103 of the microcomputer 100 to the serial communication circuit 202 of the serial parallel IC 200 by the control unit 101 of the microcomputer 100. The control circuit 201 of the serial parallel IC 200 performs initial settings (register settings) based on the signal received by the serial communication circuit 202.

[0025] After the time T2 when the initial setting is completed, the control unit 101 of the microcomputer 100 generates a serial signal including data for operating a specific primary check circuit 300, and transmits it to the serial parallel IC 200 via the serial communication circuit 103. The data for operating the specific primary check circuit 300 is data corresponding to the start signal for primary check. The specific primary check circuit 300 may include a plurality of primary check circuits 300. The control unit 101 of the microcomputer 100 generates a serial signal for operating the primary check circuit 300 corresponding to the safety circuit 400 to be inspected (primary check). The control unit 101 of the microcomputer 100 may sequentially transmit a plurality of serial signals to the serial parallel IC 200. The control circuit 201 of the serial parallel IC 200 converts the serial signal received by the serial communication circuit 202 into a signal (parallel signal) for each primary check circuit 300 based on the register setting, and transmits the signal to each primary check circuit 300 via the output circuit 203. The signal is an output signal and a start signal for starting the primary check circuit 300.

[0026] For example, when the start signal is set to "1" and the primary check circuits 300A to 300C are to be started, the microcomputer 100 transmits "111" as data corresponding to the start signal from the serial communication circuit 103 to the serial communication circuit 202 as serial data. The serial parallel IC 200 converts the received serial data into a parallel signal, and outputs "1", which is the start signal, from the output circuit 203 to each primary check circuit 300.

[0027] When the primary check circuit 300 receives a start signal from the serial-parallel IC 200, it starts operating and transmits an inspection signal for primary check to the safety circuit 400. The inspection signal is, for example, a signal indicating an abnormality for inspecting the safety circuit 400. Whether the safety circuit 400 operates normally (detects an abnormality) is inspected (primary check) by the inspection signal. When the safety circuit 400 detects an abnormality by the inspection signal, it outputs a signal including a predetermined result (inspection result) to the microcomputer 100. The microcomputer 100 receives a signal indicating the inspection result from the safety circuit 400 via the input port 104. The control unit 101 of the microcomputer 100 can determine (perform a primary check) whether the safety circuit 400 is operating normally based on the signal indicating the inspection result from the safety circuit 400 before normal operation.

[0028] When the primary check of the safety circuit 400 is completed (at time T3), the control unit 101 of the microcomputer 100 transmits a Lo signal to the serial-parallel IC 200 via the output port 102. While receiving the Lo signal, the control circuit 201 of the serial-parallel IC 200 sets the serial-parallel IC 200 to an inactive state. When the serial-parallel IC 200 is in the inactive state, the serial-parallel IC 200 does not operate. Since the serial-parallel IC 200 does not operate, a signal is not transmitted from the primary check circuit 300 to the safety circuit 400. After time T3, the microcomputer 100, the safety circuit 400, etc. operate normally. That is, for example, the safety circuit 400 can detect an abnormality in components in the vehicle.

[0029] (Operations and effects of the embodiment) In the primary check system 10 of this embodiment, at startup, the microcomputer 100 transmits an enable signal to the serial-parallel IC 200 to activate the serial-parallel IC 200. The microcomputer 100 generates a serial signal for operating a specific primary check circuit 300 and transmits it to the serial-parallel IC 200. The serial-parallel IC 200 converts the serial signal into a parallel signal and transmits a startup signal to each primary check circuit 300 including the specific primary check circuit 300. Based on the startup signal received from the serial-parallel IC 200, the specific primary check circuit 300 transmits an inspection signal to the safety circuit 400. The safety circuit 400 transmits a signal including a response (operation result) based on the inspection signal to the microcomputer 100. Thus, by using a serial signal, even if the number of primary check circuits 300 and safety circuits 400 increases, it is not necessary to increase the number of ports (terminals) of the microcomputer 100. Also, by using a serial signal, even if the number of outputs to the primary check circuit 300 (the number of check items by the primary check circuit 300) increases, it is not necessary to increase the number of ports (terminals) of the microcomputer 100. When the number of primary check circuits 300 and safety circuits 400, or the number of outputs to the primary check circuit 300 increases, for example, it can be dealt with by increasing the number of signal lines between the serial-parallel IC 200 and the primary check circuit 300. Also, by setting the serial-parallel IC 200 to an inactive state except during primary check, the signal lines for transmitting and receiving serial signals can be branched and connected to other IC chips 500. Thus, it is not necessary to provide a dedicated port for primary check in the microcomputer 100. Thereby, the number of terminals (ports) provided in the microcomputer 100 is suppressed.

[0030] As described above, the embodiments of the present invention have been explained, but these are merely examples, and the present invention is not limited to these, and various modifications based on the knowledge of those skilled in the art are possible without departing from the spirit of the claims.

Description of Symbols

[0031] 10 Primary Check System 100 Microcomputer 101 Control Unit 102 Output Port 103 Serial Communication Circuit 104 Input Port 200 Serial - Parallel IC 201 Control Circuit 202 Serial Communication Circuit 203 Output Circuit 300 Primary Check Circuit 400 Safety Circuit 500 IC Chip

Claims

1. A control unit that outputs data for primary check for a plurality of primary check circuits as a serial signal via a serial communication line, A serial / parallel conversion circuit that converts the data for primary check received by the serial signal into a parallel signal and transmits it to a plurality of primary check circuits, Before the start of the primary check, the control unit activates the serial / parallel conversion circuit, and when the primary check is completed, the control unit deactivates the serial / parallel conversion circuit. A primary check system.

2. The serial communication line has a branch line that branches in the middle, the branch line is connected to a circuit different from the serial / parallel conversion circuit, and when the primary check is completed, a serial signal is output to the different circuit via the branch line. The primary check system according to claim 1.

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