CONTROL SYSTEM, DISCONNECTION DETECTION METHOD, AND DISCONNECTION DETECTION PROGRAM

Abstract

To detect disconnection of a wiring part without adding new components in a configuration for inputting an analog sensor signal to a terminal of a semiconductor chip via the wiring part.SOLUTION: A control system has: a semiconductor chip that incorporates a processing unit, an A / D converter and a pull device circuit; a wiring part that has one end connected to a terminal to be connected to the A / D converter; and a sensor that is connected to the other terminal of the wiring part, and inputs an analog sensor signal via the wiring part. The pull device circuit comprises a switching element, and has one end connected to a ground or a power source voltage, and has the other end connected between the A / D converter and the terminal. The processing unit comprises: a switch control unit that controls an ON / OFF state of the switching element; a sensor information generation unit that generates sensor information on the basis of the sensor signal; and a disconnection detection unit that detects disconnection of the wiring part on the basis of an output of the A / D converter when the switching element is in the ON state.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a control system, a disconnection detection method, and a disconnection detection program. [Background technology]

[0002] An electronic control device is known that includes a ground terminal for grounding a shielded wire used to output a drive signal to an inductive load to ground via a drain wire, a series circuit of a resistive element and a switching element connected between a power supply and the ground terminal, and a break detection unit that detects a break in the drain wire by switching the switching element on and off. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-139787 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which an analog sensor signal is input to a terminal of a semiconductor chip via a wiring portion, it would be useful to realize a mechanism capable of detecting a break in the wiring portion at low cost without adding new components.

[0005] The present disclosure has been made to solve the above problems, and has as its purpose to detect a break in a wiring section in a configuration in which an analog sensor signal is input to a terminal of a semiconductor chip via a wiring section, without adding any new components. [Means for solving the problem]

[0006] In order to solve the above problem, one aspect of the present disclosure is a semiconductor chip including a processing unit, an A / D converter, and a pull device circuit; a wiring portion having one end connected to a terminal connected to the A / D converter; a sensor connected to the other end of the wiring portion and configured to input an analog sensor signal to the terminal via the wiring portion, the pull device circuit includes a switching element, one end of which is connected to a ground or a power supply voltage, and the other end of which is connected between the A / D converter and the terminal; The processing unit includes: A switch control unit that controls the on / off state of the switching element; a sensor information generating unit that generates sensor information based on the sensor signal; and a disconnection detection unit that detects a disconnection of the wiring portion based on an output of the A / D converter when the switching element is in an on state. A control system is provided. Effect of the Invention

[0007] According to the present disclosure, in a configuration in which an analog sensor signal is input to a terminal of a semiconductor chip via a wiring section, it is possible to detect a break in the wiring section without adding a new component (by using a pull device circuit built into the semiconductor chip). [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of one embodiment of a hydraulic pressure generating device. [Diagram 2] 1 is a configuration diagram illustrating an embodiment of a motor control device. [Diagram 3] 2 is a schematic diagram showing the internal configuration of a microcomputer and a temperature sensor. FIG. [Figure 4] FIG. 4 is an explanatory diagram of output characteristics of a temperature sensor. [Diagram 5] FIG. 13 is an explanatory diagram of a disconnection in a wiring portion. [Figure 6] 10 is an explanatory diagram of the output characteristics of the A / D converter when the pull-up circuit is turned on during normal operation. FIG. [Figure 7]11 is an explanatory diagram of the output characteristics of the A / D converter when a pull-up circuit is turned on in the case where a break occurs in a wiring portion. FIG. [Figure 8] FIG. 13 is an explanatory diagram of a ground fault in a temperature sensor. [Figure 9] 11 is a timing chart showing a case where a disconnection detection process is performed by a disconnection detection unit during an initialization process of a microcomputer. [Figure 10] 13 is a timing chart of a method for determining a fault related to a short-to-power fault by a sensor fault detection unit. [Figure 11] 4 is a timing chart of a fault determination method for a ground fault by a sensor fault detection unit. [Figure 12] 11 is a timing chart showing a case where a disconnection detection process is performed by a disconnection detection unit when the microcomputer is in a sleep mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] FIG. 1 is a schematic diagram of an embodiment of a hydraulic pressure generating device 1.

[0011] The hydraulic pressure generating device 1 is a device that generates hydraulic pressure and is preferably mounted on a vehicle. The hydraulic pressure generating device 1 includes a motor drive system 2 and a hydraulic pump 3, as shown in FIG.

[0012] The motor drive system 2 includes a motor control device 10 and a motor 12 .

[0013] The motor control device 10 controls the hydraulic pump 3 by controlling the motor 12. The motor control device 10 is a processing device including a microcomputer (abbreviation of microcomputer) 110 and the like. The hardware configuration of the motor control device 10 is arbitrary and can be similar to that of an in-vehicle ECU (Electronic Control Unit).

[0014] The output shaft 12a of the motor 12 functions as a drive shaft of the hydraulic pump 3. The motor 12 is a three-phase brushless motor, but the number of phases is not limited to this, and the detailed configuration is optional. The motor 12 may be directly connected to the hydraulic pump 3, or may be connected via another mechanism (not shown) or the like.

[0015] The hydraulic pump 3 is an electric pump, which draws oil from a tank 31 and discharges it to a supply path 32 when driven.

[0016] In this way, the oil pressure generating device 1 of this embodiment generates oil pressure by driving the hydraulic pump 3 via the motor drive system 2. The oil pressure generated by the hydraulic pump 3 (i.e., the oil discharged from the hydraulic pump 3) can be used to drive actuators, cool heat-generating components of various on-board electronic devices, lubricate moving parts, and the like.

[0017] Fig. 2 is a schematic diagram showing an embodiment of the motor control device 10. Fig. 2 also shows the host ECU 4 as a related component. Fig. 3 is a schematic diagram showing the internal configuration of the microcomputer 110 and the temperature sensor 122.

[0018] The host ECU 4 is an example of a control device that is higher in level than the motor control device 10, and issues various commands to the motor control device 10.

[0019] As shown in FIG. 2, the motor control device 10 includes a microcomputer 110 and a drive device 120.

[0020] The microcomputer 110 controls the motor 12 via the drive device 120 in response to various commands from the host ECU 4. The microcomputer 110 also monitors the temperature of the drive device 120 based on sensor information (described later) from a temperature sensor 122 of the drive device 120.

[0021] The microcomputer 110 is in the form of a semiconductor chip, and includes a processing unit 111, an A / D converter 112, a pull-up circuit 113, and a pull-down circuit 114, as shown in FIG.

[0022] The processing unit 111 includes a CPU (Central Processing Unit), a storage device, and the like, and performs various types of arithmetic processing.

[0023] The A / D converter 112 converts an input analog signal into a digital signal and outputs the digital signal. In this embodiment, an electrical signal is input to the A / D converter 112 from the temperature sensor 122 of the driving device 120. The A / D converter 112 inputs the output in the form of a digital signal to the processing unit 111.

[0024] The pull-up circuit 113 has one end connected to a power supply voltage Vcc (e.g., 5 V) and the other end connected to an input line 1121 to the A / D converter 112. The input line 1121 is a wiring inside the microcomputer 110, and has one end connected to a terminal Tm1 of the microcomputer 110 and the other end connected to the A / D converter 112.

[0025] The pull-up circuit 113 includes a switching element SW1 and a resistor R1. The switching element SW1 is, for example, in the form of a transistor (for example, a bipolar transistor). The resistor R1 is a fixed resistor and may have a resistance value in the range of, for example, 25 kΩ to 127 kΩ.

[0026] The pull-up circuit 113 can turn its own function on / off by turning on / off the switching element SW1. Hereinafter, turning on / off the pull-up circuit 113 means that turning on / off the switching element SW1 turns on / off the function of the pull-up circuit 113.

[0027] The pull-down circuit 114 has one end connected to ground and the other end connected to an input line 1121 to the A / D converter 112. The pull-down circuit 114 includes a switching element SW2 and a resistor R2. The switching element SW2 is in the form of, for example, a transistor (for example, a bipolar transistor). The resistor R2 is a fixed resistor and may have a resistance value in the range of, for example, 25 kΩ to 127 kΩ.

[0028] The pull-down circuit 114 can turn its own function on / off by turning on / off the switching element SW2. Hereinafter, turning on / off the pull-down circuit 114 means that turning on / off the switching element SW2 turns on / off the function of the pull-down circuit 114.

[0029] The driving device 120 is in the form of, for example, a control board, and various electronic components are mounted on the driving device 120. The driving device 120 includes a driving circuit 121 and a temperature sensor 122.

[0030] The drive circuit 121 includes, for example, an inverter and a driver, and controls the current flowing through the motor 12 in response to a drive signal from the microcomputer 110 .

[0031] The temperature sensor 122 is in the form of, for example, a thermistor, and generates an electrical signal (analog signal) corresponding to the temperature at the location where it is installed.

[0032] The temperature sensor 122 is connected to a terminal Tm1 of the microcomputer 110 via a wiring section 130. One end of the wiring section 130 is connected to the terminal Tm1 of the microcomputer 110, and the other end is connected to a terminal Tm2 of the temperature sensor 122.

[0033] In the example shown in FIG. 3, the temperature sensor 122 includes a thermistor 1222, a resistor 1223, and a capacitor 1224.

[0034] The thermistor 1222 is in the form of a variable resistor whose resistance value changes with temperature. The thermistor 1222 may be, for example, a resistor whose resistance value changes with temperature in the range of 0.3 kΩ to 195 kΩ. The thermistor 1222 is connected in series with resistor 1223 between a power supply voltage 1221 (5 V in this example) and ground.

[0035] The resistor 1223 is in the form of a fixed resistor. The resistor 1223 is connected in series with the thermistor 1222. The resistor 1223 is arranged on the ground side. In a modified example, the thermistor 1222 may be arranged on the ground side, and the resistor 1223 may be arranged on the power supply voltage 1221 side. The resistance value of the resistor 1223 is fixed and may be, for example, about 5 kΩ.

[0036] One end of the capacitor 1224 is connected to a connection point P1 between the thermistor 1222 and the resistor 1223, and the other end is connected to the ground. A charge corresponding to the potential of the connection point P1 accumulates in the capacitor 1224.

[0037] A connection point P1 between the thermistor 1222 and resistor 1223 is connected to terminal Tm2 of temperature sensor 122. A voltage is generated at connection point P1 between the thermistor 1222 and resistor 1223, the voltage being obtained by dividing power supply voltage 1221 (5V in this example) by the resistance value of the thermistor 1222 and the resistance value of resistor 1223. This voltage value changes according to the resistance value of the thermistor 1222, so temperature information can be obtained based on this voltage value.

[0038] Fig. 4 is an explanatory diagram of the output characteristics of temperature sensor 122, with the horizontal axis representing actual temperature and the vertical axis representing the output of A / D converter 112 (indicated as "A / D recognized voltage" in Fig. 4), showing a curve of the output characteristics of temperature sensor 122. Fig. 5 is an explanatory diagram of a break in wiring section 130, with the break location being diagrammatically indicated by the letters "break" together with an X mark.

[0039] 4, the output of A / D converter 112, which corresponds to the output of temperature sensor 122, increases as the actual temperature increases. By utilizing such a characteristic, temperature information can be obtained based on the output of A / D converter 112.

[0040] 5, in a configuration in which the microcomputer 110 and the temperature sensor 122 are connected via a wiring unit 130, a break may occur in the wiring unit 130. Such a break may cause the microcomputer 110 to be unable to obtain accurate temperature information. When a break occurs in the wiring unit 130, a voltage of an indefinite value (an input voltage of the A / D converter 112) is generated at the terminal Tm1 of the microcomputer 110.

[0041] Such inconveniences occur not only due to breakage in wiring section 130, but also due to breakage in wiring section 131 between terminal Tm1 and connection point P3 in input line 1121 in microcomputer 110, and breakage in wiring section 132 between terminal Tm2 and connection point P4 in temperature sensor 122. Note that connection point P3 corresponds to the connection point with pull-up circuit 113 in input line 1121, and connection point P4 corresponds to the connection point with capacitor 1224 in the signal line from connection point P1 to terminal Tm2. In the following, for simplicity of explanation, breakage in wiring section 130 will be representatively explained, but the same applies to breakage in wiring section 131 and wiring section 132.

[0042] In this embodiment, the microcomputer 110 detects a break in the wiring section 130 by using the pull-up circuit 113 or the pull-down circuit 114. Hereinafter, a method of detecting a break in the wiring section 130 will be described in detail.

[0043] 6 and 7 are explanatory diagrams of a detection method using the pull-up circuit 113, and are explanatory diagrams of the output characteristics of the A / D converter 112 when the pull-up circuit 113 is turned on, in which the horizontal axis represents the actual temperature and the vertical axis represents the output of the A / D converter 112 (indicated as "A / D recognition voltage" in Figs. 6 and 7), and the curves of the output characteristics of the A / D converter 112 are shown. Fig. 6 shows an output characteristic 600 of the A / D converter 112 when no break occurs in the wiring section 130, and Fig. 7 shows an output characteristic 630 of the A / D converter 112 when a break occurs in the wiring section 130. Note that, for comparison, the characteristic 610 shown in Fig. 4 is shown by a dotted line in Fig. 6.

[0044] If there is no break in the wiring section 130, as shown in FIG. 6, the output of the A / D converter 112 is affected by the output of the temperature sensor 122 and fluctuates within a certain range that is significantly greater than 0 V and significantly less than 5 V.

[0045] 7, when a break occurs in the wiring unit 130, the output of the A / D converter 112 is not affected by the output of the temperature sensor 122 and remains at the voltage value pulled up by the pull-up circuit 113. At this time, the output of the A / D converter 112 becomes significantly higher than the first predetermined threshold value.

[0046] Therefore, it can be seen that a break in wiring section 130 can be detected based on the difference in output from A / D converter 112, i.e., the difference between a case where no break occurs in wiring section 130 and a case where a break occurs in wiring section 130.

[0047] It should be noted that the substantially same result occurs when the pull-down circuit 114 is turned on instead of the pull-up circuit 113. In this case, when a break occurs in the wiring section 130, the output of the A / D converter 112 sticks to the voltage value pulled down by the pull-down circuit 114. At this time, the output of the A / D converter 112 becomes approximately 0 V. Therefore, it can be seen that a break in the wiring section 130 can be detected based on such a difference in the output of the A / D converter 112.

[0048] In this manner, according to this embodiment, a break in the wiring portion 130 can be detected by utilizing the pull-up circuit 113 or the pull-down circuit 114.

[0049] Next, the function of the processing unit 111 of the microcomputer 110 will be described in detail with reference to Fig. 2 and Fig. 6 again and Fig. 8 onwards. An example in which the pull-up circuit 113 is used to detect a break in the wiring unit 130 will be described below, but as mentioned above, the pull-down circuit 114 may also be used. When the pull-up circuit 113 is used, the pull-down circuit 114 is turned off, and when the pull-down circuit 114 is used, the pull-up circuit 113 is turned off. In a modified example, both the pull-up circuit 113 and the pull-down circuit 114 may be used in a time-division manner.

[0050] 2, the microcomputer 110 includes a switch control unit 200, a sensor information generation unit 210, a disconnection detection unit 220, and a sensor failure detection unit 230. The switch control unit 200, the sensor information generation unit 210, the disconnection detection unit 220, and the sensor failure detection unit 230 can be realized by the CPU of the processing unit 111 executing a program in a storage device.

[0051] The switch control unit 200 controls the on / off state of the switching element SW1 of the pull-up circuit 113. In this embodiment, the switch control unit 200 turns on the switching element SW1 while a predetermined condition is satisfied. In this case, the switch control unit 200 turns on the switching element SW1 when the predetermined condition is satisfied, and turns off the switching element SW1 when the predetermined condition is no longer satisfied.

[0052] 6, the output characteristic 600 of the A / D converter 112 when the pull-up circuit 113 is on is different from the output characteristic 610 of the A / D converter 112 when the pull-up circuit 113 is off. Therefore, in a configuration in which temperature information is generated based on a calculation formula adapted to the output characteristic 610, if temperature information is generated based on the output characteristic 600, accurate temperature information cannot be obtained. In other words, when temperature information is generated based on the output characteristic 600 using a calculation formula adapted to the output characteristic 610, it is affected by fluctuations that may occur due to the pull-up circuit 113, and therefore accurate temperature information cannot be obtained. Note that adapting a new calculation formula based on the output characteristic 600 results in a complicated calculation formula such as a high-order function, which is disadvantageous in terms of calculation load.

[0053] In consideration of this, the predetermined condition is preferably adapted to be satisfied only during a period when it is not necessary to obtain temperature information or when it is not necessary to obtain highly accurate temperature information. For example, the predetermined condition may be satisfied in relation to initialization or sleep mode. Specifically, the predetermined condition is satisfied over a part or the entirety of the initialization period of the microcomputer 110 and / or over a part or the entirety of the period of the sleep mode of the microcomputer 110. This allows the pull-up circuit 113 to be turned on under appropriate conditions when it is not necessary to obtain temperature information.

[0054] The sensor information generating unit 210 generates temperature information as sensor information based on the sensor signal from the temperature sensor 122. In this embodiment, as described above, if the temperature information is generated based on the output of the A / D converter 112 when the pull-up circuit 113 is on using a calculation formula adapted to the output characteristic 610, accurate temperature information cannot be obtained. Therefore, the sensor information generating unit 210 generates temperature information based on the sensor signal from the temperature sensor 122 when the pull-up circuit 113 is off using a calculation formula adapted to the output characteristic 610. This makes it possible to detect a break in the wiring unit 130 using the pull-up circuit 113, while preventing problems caused by the pull-up circuit 113 (deterioration in the accuracy of the temperature information).

[0055] The disconnection detection unit 220 detects a disconnection of the wiring unit 130 based on the output of the A / D converter 112 when the pull-up circuit 113 is on. The method of detecting a disconnection of the wiring unit 130 is as described above with reference to FIG. 6. Specifically, the disconnection detection unit 220 detects a disconnection of the wiring unit 130 when the output of the A / D converter 112 when the pull-up circuit 113 is on exceeds a first predetermined threshold. The first predetermined threshold may be set to be greater than the upper limit value of the range that the output of the A / D converter 112 can take when the pull-up circuit 113 is on and when no disconnection of the wiring unit 130 occurs. For example, in the example shown in FIG. 6, the output characteristic 600 fluctuates within a range having an upper limit value significantly lower than 4.9V. Therefore, in this case, the first predetermined threshold may be set to 4.9V.

[0056] In a configuration using the pull-down circuit 114, the disconnection detection unit 220 detects a disconnection of the wiring unit 130 when the output of the A / D converter 112 falls below a second predetermined threshold when the pull-down circuit 114 is on. The second predetermined threshold may be set to be smaller than the lower limit of the range of the output of the A / D converter 112 when the pull-down circuit 114 is on and no disconnection of the wiring unit 130 has occurred. For example, the second predetermined threshold may be set to a value slightly larger than 0 (e.g., about 0.025 V).

[0057] When the disconnection detection unit 220 detects a disconnection in the wiring unit 130, the disconnection detection unit 220 may generate information indicating that fact (for example, diagnostic information). In this case, the host ECU 4 may generate an output instruction for an alarm or the like based on the information.

[0058] The sensor failure detection unit 230 detects various failures of the temperature sensor 122 based on the output of the A / D converter 112 when the pull-up circuit 113 is in the off state. Therefore, the sensor failure detection unit 230 operates together with the sensor information generation unit 210 based on the output of the A / D converter 112 when the pull-up circuit 113 is in the off state.

[0059] Specifically, the sensor failure detection unit 230 detects a short-to-power fault in the temperature sensor 122 when the output of the A / D converter 112 when the pull-up circuit 113 is in an off state exceeds a third predetermined threshold. When a short-to-power fault occurs in the temperature sensor 122, the output of the A / D converter 112 sticks to a value corresponding to the power supply voltage 1221, similar to the output characteristic 630 of the A / D converter 112 when a break occurs in the wiring unit 130 (see FIG. 7). Therefore, in this case, the short-to-power fault in the temperature sensor 122 can be detected by the third predetermined threshold that is the same as the first predetermined threshold used for break detection by the break detection unit 220. That is, the third predetermined threshold may be the same as the first threshold used for break detection by the break detection unit 220.

[0060] Also, when the output of the A / D converter 112 when the pull-up circuit 113 is in an off state falls below a fourth predetermined threshold, a ground fault in the temperature sensor 122 is detected. A ground fault in the temperature sensor 122 occurs, for example, due to a break in a signal line from the power supply voltage 1221 to the connection point P1, as shown in FIG. 8. In this case, the power supply voltage 1221 is also disconnected from the terminal Tm2 of the temperature sensor 122, so that the terminal Tm2 of the temperature sensor 122 is at ground potential. Therefore, when a ground fault occurs in the temperature sensor 122, the output of the A / D converter 112 sticks to 0V. Therefore, in this case, a ground fault in the temperature sensor 122 can be detected by a fourth predetermined threshold that is the same as the second predetermined threshold used for disconnection detection by the disconnection detection unit 220. That is, the fourth predetermined threshold may be the same as the second predetermined threshold used for disconnection detection using the pull-down circuit 114.

[0061] When the sensor failure detection unit 230 detects a power fault or a ground fault in the temperature sensor 122, it may generate failure information (e.g., diagnostic information) indicating that fact. In this case, the host ECU 4 may generate an output instruction such as an alarm based on such information. The failure information may include information indicating the type of failure (power fault or ground fault).

[0062] Next, an example of the operation of the microcomputer 110 related to disconnection detection and the like will be described with reference to FIGS.

[0063] Fig. 9 is a timing chart when the disconnection detection unit 220 performs the disconnection detection process during the initialization process of the microcomputer 110. In Fig. 9, from the top, a time series waveform of the power supply voltage Vcc, a time series of the contents of the software processing, and a time series of the on / off state of the pull-up circuit 113 are shown. Figs. 10 and 11 are timing charts of a failure determination method by the sensor failure detection unit 230. In Figs. 10 and 11, from the top, a time series of the output of the temperature sensor 122 corresponding to the output of the A / D converter 112 (represented as "sensor output" in Figs. 10 and 11) and a time series of the determination result of the sensor failure are shown.

[0064] 9, for example, when the power supply voltage Vcc rises at time t0 with the start of the vehicle, the initialization process of the microcomputer 110 is executed during the period from time t0 to time t1. The disconnection detection process by the disconnection detection unit 220 is executed during this period from time t0 to time t1. Specifically, during the period from time t0 to time t1, the pull-up circuit 113 is turned on, and the disconnection detection process by the disconnection detection unit 220 is executed based on the output of the A / D converter 112 when the pull-up circuit 113 is in the on state.

[0065] When the initialization process of the microcomputer 110 is completed, the pull-up circuit 113 is turned off at time t1, and the steady-state process is executed. At this time, the sensor information generating unit 210 and the sensor failure detecting unit 230 function to perform sensor measurement (generation of temperature information) and failure determination of the temperature sensor 122. In this case, the failure determination of the temperature sensor 122 is realized, for example, in the manner shown in FIG. 10 and FIG. 11. In each of FIG. 10 and FIG. 11, a short-to-power fault and a short-to-ground fault occur at time t4 and t5. Specifically, in the example shown in FIG. 10, a short-to-power fault occurs at time t4, and the output of the temperature sensor 122 corresponding to the output of the A / D converter 112 is stuck at a value that exceeds the upper limit value in normal times (a value that exceeds the third predetermined threshold value). In this case, the short-to-power fault is detected at the failure determination timing t6, and the determination result of the sensor failure changes from "normal" to "abnormal". 11, a ground fault occurs at time t5, and the output of the temperature sensor 122 corresponding to the output of the A / D converter 112 is stuck at a value below the lower limit value in normal operation (a value below the fourth predetermined threshold value). In this case, the ground fault is detected at the fault determination timing t7, and the determination result of the sensor fault changes from "normal" to "abnormal".

[0066] In the example shown in FIG. 9, the pull-up circuit 113 is on throughout the entire period of the initialization process of the microcontroller 110, but it may be on only during the period during which the disconnection detection process is performed by the disconnection detection unit 220.

[0067] Fig. 12 is a timing chart when the disconnection detection unit 220 performs the disconnection detection process when the microcomputer 110 is in the sleep mode. In Fig. 12, similar to Fig. 9, from the top, a time series waveform of the power supply voltage Vcc, a time series of the contents of the software processing, and a time series of the ON / OFF state of the pull-up circuit 113 are shown.

[0068] 12, the microcomputer 110 transitions to a sleep mode during the period from time t2 to time t3. The disconnection detection unit 220 executes the disconnection detection process during the period from time t2 to time t3. Specifically, the pull-up circuit 113 is turned on during the period from time t2 to time t3, and the disconnection detection unit 220 executes the disconnection detection process based on the output of the A / D converter 112 when the pull-up circuit 113 is in the on state. When the sleep mode of the microcomputer 110 ends, the pull-up circuit 113 is turned off at time t3, and normal processing is executed. At this time, the sensor information generation unit 210 and the sensor failure detection unit 230 function to execute sensor measurement (generation of temperature information) and failure determination of the temperature sensor 122.

[0069] 12, the pull-up circuit 113 is on throughout the entire period of the sleep mode of the microcomputer 110, but it may be on only during the period during the entire sleep mode during which the disconnection detection process is executed by the disconnection detection unit 220. Also, it is not necessary to execute the disconnection detection process for each sleep mode, and the disconnection detection process may be executed in a sleep mode after a predetermined period has elapsed since the previous disconnection detection process.

[0070] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included.

[0071] For example, in the above-described embodiment, the temperature sensor 122 is a sensor that inputs an analog sensor signal to the microcomputer 110, but such a sensor may be a sensor other than the temperature sensor 122. For example, the sensor that inputs an analog sensor signal to the microcomputer 110 may be a current sensor, a voltage sensor, a rotation angle sensor, or the like.

[0072] In addition, the following supplementary notes are disclosed regarding the above embodiment.

[0073] [Appendix 1] A semiconductor chip (e.g., a microcomputer 110) incorporating a processing unit (111), an A / D converter (112), and pull device circuits (113, 114), Wiring portions 130, 131, and 132 each having one end connected to a terminal connected to the A / D converter; a sensor (e.g., a temperature sensor 122) connected to the other end of the wiring portion and inputting an analog sensor signal to the terminal via the wiring portion, the pull device circuit includes switching elements (SW1, SW2), one end of which is connected to a ground or a power supply voltage, and the other end of which is connected between the A / D converter and the terminal; The processing unit includes: A switch control unit (200) that controls the on / off state of the switching element; A sensor information generating unit (210) that generates sensor information based on the sensor signal; and a disconnection detection unit (220) that detects a disconnection of the wiring portion based on an output of the A / D converter when the switching element is in an on state. A control system (for example, a motor drive system 2 or a motor control device 10).

[0074] According to the configuration of Appendix 1, in a configuration in which an analog sensor signal is input to a terminal of a semiconductor chip via a wiring section, a control system can be obtained that is capable of detecting a break in the wiring section without adding any new components (by utilizing a pull device circuit built into the semiconductor chip).

[0075] [Appendix 2] The sensor information generating unit generates the sensor information based on an output of the A / D converter when the switching element is in an off state. 2. The control system of claim 1.

[0076] According to the configuration of Supplementary Note 2, highly accurate sensor information can be obtained in a manner that is not affected by the pull device circuit.

[0077] [Appendix 3] The switch control unit turns on the switching element while a predetermined condition is satisfied. 3. The control system of claim 1 or 2.

[0078] According to the configuration of Supplementary Note 3, the period during which the pull device circuit and therefore the disconnection detection unit function can be appropriately limited.

[0079] [Appendix 4] The predetermined condition is satisfied in relation to an initialization mode or a sleep mode. 4. The control system of claim 3.

[0080] According to the configuration of Supplementary Note 4, the pull device circuit and the associated disconnection detection unit can be made to function in association with the initialization or sleep mode, which are timings when there is little need to obtain sensor information.

[0081] [Appendix 5] the disconnection detection unit detects a disconnection of the wiring portion when an output of the A / D converter exceeds a first predetermined threshold value or falls below a second predetermined threshold value when the switching element is in an on state. 5. A control system according to any one of claims 1 to 4.

[0082] According to the configuration of Supplementary Note 5, a break in the wiring portion can be detected with high accuracy based on the relationship between the output of the A / D converter and the predetermined threshold value.

[0083] [Appendix 6] The processing unit further includes a sensor failure detection unit (230), the sensor fault detection unit detects a short-to-power fault in the sensor when an output of the A / D converter when the switching element is in an off state exceeds a third predetermined threshold, and detects a short-to-ground fault in the sensor when an output of the A / D converter when the switching element is in an off state falls below a fourth predetermined threshold. 6. The control system of claim 5.

[0084] According to the configuration of Supplementary Note 6, it is possible to detect not only disconnection of the wiring portion but also a short-to-power fault or a short-to-ground fault in the sensor. Furthermore, since a short-to-power fault or a short-to-ground fault in the sensor can be detected based on the output used to obtain the sensor information, it is possible to quickly detect the fault when it occurs.

[0085] [Appendix 7] A method for detecting a broken wire in a control system, comprising: The control system includes: a semiconductor chip incorporating a processing unit, an A / D converter, and a pull device circuit; a wiring portion having one end connected to a terminal connected to the A / D converter; a sensor connected to the other end of the wiring portion and configured to input an analog sensor signal to the terminal via the wiring portion, the pull device circuit includes a switching element, one end of which is connected to a ground or a power supply voltage, and the other end of which is connected between the A / D converter and the terminal; The disconnection detection method includes: controlling an on / off state of the switching element by the processing unit; generating sensor information based on the sensor signal by the processing unit; and detecting a break in the wiring portion based on an output of the A / D converter when the switching element is in an on state. Disconnection detection method.

[0086] According to the configuration of Appendix 7, in a control system in which an analog sensor signal is input to a terminal of a semiconductor chip via a wiring section, a disconnection detection method can be obtained that can detect a disconnection in the wiring section without adding a new component (by utilizing a pull device circuit built into the semiconductor chip).

[0087] [Appendix 8] A program for detecting a broken wire in a control system, comprising: The control system includes: a semiconductor chip incorporating a processing unit, an A / D converter, and a pull device circuit; a wiring portion having one end connected to a terminal connected to the A / D converter; a sensor connected to the other end of the wiring portion and configured to input an analog sensor signal to the terminal via the wiring portion, the pull device circuit includes a switching element, one end of which is connected to a ground or a power supply voltage, and the other end of which is connected between the A / D converter and the terminal; The disconnection detection program includes: A process of controlling an on / off state of the switching element; generating sensor information based on the sensor signal; detecting a break in the wiring portion based on an output of the A / D converter when the switching element is in an on state; Disconnection detection program.

[0088] According to the configuration of Appendix 8, in a control system in which an analog sensor signal is input to a terminal of a semiconductor chip via a wiring section, it is possible to obtain a break detection program that can detect a break in the wiring section without adding a new component (by utilizing a pull device circuit built into the semiconductor chip). [Explanation of symbols]

[0089] 1. Hydraulic pressure generator 2 Motor drive system (an example of a control system) 3. Hydraulic pump 4 Upper ECU 10 Motor control device (an example of a control system) 12 Motor 12a Output shaft 31 Tank 32 Supply route 110 Microcomputer 111 Processing section 112 A / D Converter 113 Pull-up circuit (an example of a pull device circuit) 114 Pull-down circuit (an example of a pull device circuit) 120 Drive unit 121 Drive circuit 122 Temperature Sensor 130 Wiring section 131 Wiring section 132 Wiring section 200 Switch control section 210 Sensor information generation unit 220 Disconnection detection unit 230 Sensor failure detection unit 600 Output characteristics 630 Output characteristics 1121 Input Line 1221 Power supply voltage 1222 Thermistor 1223 Resistance 1224 Capacitor

Claims

1. a semiconductor chip incorporating a processing unit, an A / D converter, and a pull device circuit; a wiring portion having one end connected to a terminal connected to the A / D converter; a temperature sensor connected to the other end of the wiring portion and inputting an analog sensor signal to the terminal via the wiring portion, the pull device circuit includes a switching element, one end of which is connected to a ground or a power supply voltage, and the other end of which is connected between the A / D converter and the terminal; When no break occurs in the wiring portion, the output of the A / D converter when the switching element is in an on state is an output that is influenced by the output of the temperature sensor, When a break occurs in the wiring portion, the break prevents the sensor signal from being input to the terminal, and the output of the A / D converter when the switching element is in an on state becomes an output that is not affected by the temperature sensor, The processing unit includes: A switch control unit that controls an on / off state of the switching element; a sensor information generating unit that generates temperature information as sensor information based on the sensor signal; a disconnection detection unit that detects a disconnection of the wiring portion based on the fact that an output of the A / D converter when the switching element is in an on state is an output that is not affected by the temperature sensor, The switch control unit turns on the switching element during a part or the entire period of the sleep mode. Control system.

2. The sensor information generating unit generates the sensor information based on an output of the A / D converter when the switching element is in an off state. The control system of claim 1 .

3. When the pull device circuit is a pull-up circuit, one end of the pull device circuit is connected to the power supply voltage and the other end is connected between the A / D converter and the terminal; When the pull device circuit is a pull-down circuit, one end of the pull device circuit is connected to ground and the other end is connected between the A / D converter and the terminal; when the pull device circuit is the pull-up circuit, the disconnection detection unit detects a disconnection in the wiring portion by determining that the output of the A / D converter is an output that is not affected by the temperature sensor when the output exceeds a first predetermined threshold that is set to be greater than an upper limit value of a possible range of an output affected by the output of the temperature sensor, and When the pull device circuit is the pull-down circuit, the disconnection detection unit detects a disconnection in the wiring portion by determining that the output of the A / D converter is an output that is not affected by the temperature sensor when the output falls below a second predetermined threshold value that is set to be smaller than a lower limit value of a possible range of an output affected by the output of the temperature sensor. A control system according to claim 1 or 2.

4. A method for detecting a broken wire in a control system, comprising: The control system includes: a semiconductor chip incorporating a processing unit, an A / D converter, and a pull device circuit; a wiring portion having one end connected to a terminal connected to the A / D converter; a temperature sensor connected to the other end of the wiring portion and inputting an analog sensor signal to the terminal via the wiring portion, the pull device circuit includes a switching element, one end of which is connected to a ground or a power supply voltage, and the other end of which is connected between the A / D converter and the terminal; When no break occurs in the wiring portion, the output of the A / D converter when the switching element is in an on state is an output that is influenced by the output of the temperature sensor, When a break occurs in the wiring portion, the break prevents the sensor signal from being input to the terminal, and the output of the A / D converter when the switching element is in an on state becomes an output that is not affected by the temperature sensor, The disconnection detection method includes: controlling an on / off state of the switching element by the processing unit; generating temperature information as sensor information based on the sensor signal by the processing unit; and detecting a break in the wiring portion based on the fact that an output of the A / D converter when the switching element is in an on state is an output that is not affected by the temperature sensor. The switching element is turned on during part or the entire period of the sleep mode. Disconnection detection method.

5. A program for detecting a broken wire in a control system, comprising: The control system includes: a semiconductor chip incorporating a processing unit, an A / D converter, and a pull device circuit; a wiring portion having one end connected to a terminal connected to the A / D converter; a temperature sensor connected to the other end of the wiring portion and inputting an analog sensor signal to the terminal via the wiring portion, the pull device circuit includes a switching element, one end of which is connected to a ground or a power supply voltage, and the other end of which is connected between the A / D converter and the terminal; When no break occurs in the wiring portion, the output of the A / D converter when the switching element is in an on state is an output that is influenced by the output of the temperature sensor, When a break occurs in the wiring portion, the break prevents the sensor signal from being input to the terminal, and the output of the A / D converter when the switching element is in an on state becomes an output that is not affected by the temperature sensor, The disconnection detection program includes: A process of controlling an on / off state of the switching element; A process of generating temperature information as sensor information based on the sensor signal; and detecting a break in the wiring portion based on the fact that an output of the A / D converter when the switching element is in an on state is an output that is not affected by the temperature sensor. Also, causing the processing unit to execute control to turn on the switching element during a part or the entire period of a sleep mode. Disconnection detection program.

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