JP2011178237A - Signal input device and on-vehicle processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal input device and an on-vehicle processing system which can effectively utilize input/output ports provided on a signal processing device, improve reliability and safety by detecting an abnormality by itself and notifying it to the signal processing device, and reduce current consumption by shortening the processing time of the signal processing device related to signal input processing. <P>SOLUTION: The signal input device 2, provided with a plurality of input/output control circuits 20 having multiplexers, is disposed between a microcomputer 1 and a plurality of switches. The signal input device 2 selects signals from a plurality of the switches and input the signals to the microcomputer 1. The multiplexers of the signal input device 2 select signals according to a common selection signal from the microcomputer 1. An abnormality detection section is provided in each input/output control circuit 20 and if an abnormality is detected by any one of the control circuits, an OR circuit 32 notifies it to the microcomputer 1. The signal input device 2 also returns the selection signal from the microcomputer 1 to the microcomputer 1 by a returning section 31. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a signal input device that inputs a plurality of output signals from switches or sensors to a signal processing device such as a microcomputer, and an in-vehicle processing system in which the signal input device and the signal processing device are mounted on a vehicle. About.

  In recent years, the number of electronic devices mounted on vehicles has increased, and the number of signal lines connected to electronic control units such as ECUs (Electronic Control Units) that control these electronic devices has increased. The number of input signals is increasing. Since the number of input / output ports that can be provided in the microcomputer is limited, there arises a problem that the number of ports of the microcomputer is insufficient when the input signal increases. For this reason, a system is used in which a shortage of ports of the microcomputer is eliminated by selecting one signal from a plurality of signals by a signal selection circuit such as a multiplexer and inputting it to the microcomputer.

  For example, in Patent Document 1, there is a signal selection circuit capable of selecting a plurality of input signal lines at an input / output port of a one-channel microcomputer and reading an input signal on the selected input signal line at the input / output port. Proposed. In this signal selection circuit, the microcomputer outputs a control signal from the input / output port, the counter generates a selection signal using the rising edge of the control signal, gives it to the decoding circuit, and the multiplexer receives a plurality of inputs according to the output signal of the decoding circuit A predetermined signal line is selected from the signal lines, and the output signal of the multiplexer is input to the input / output port of the microcomputer that has output the control signal.

JP 11-249769 A

  The signal selection circuit described in Patent Document 1 is realized by an IC (Integrated Circuit) other than the microcomputer. In an electronic control unit mounted on a vehicle, in order to improve reliability and safety, it is desirable to mount a function for detecting an abnormality such as a failure in a microcomputer. However, even when the abnormality detection function is installed in the microcomputer, the microcomputer cannot detect an abnormality that has occurred in the IC outside the microcomputer, such as a signal selection circuit, and the reliability and safety are reduced. There is.

  Further, in the configuration in which a plurality of signals are sequentially switched and input to the microcomputer by the multiplexer, there is a problem that the processing time of the microcomputer increases because it takes time to complete the input of all signals. In particular, when the vehicle engine is stopped, the electric power stored in the battery is supplied to the electronic control unit. Therefore, the microcomputer is operated in a low power consumption operation state such as a sleep mode in order to reduce current consumption. However, even in the low power consumption operation state, the microcomputer needs to monitor the input signal intermittently, and in this case, the current consumption temporarily increases. For this reason, when the processing time required for monitoring the input signal is increased, the current consumption by the microcomputer is increased, and there is a possibility that the battery is accelerated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to enable effective use of input / output ports provided in a signal processing device such as a microcomputer and to input signals. An object of the present invention is to provide a signal input device and an in-vehicle processing system that can reduce the current consumption by shortening the processing time of the signal processing device for processing.

  Another object of the present invention is to provide a signal input device and an in-vehicle processing system that can improve reliability and safety by detecting an abnormality and notifying the signal processing device. is there.

  A signal input device according to the present invention is interposed between a signal processing device and one or a plurality of other devices that output signals to be input to the signal processing device, and a plurality of signals output by the other devices. In the signal input device for inputting to the signal processing device, a plurality of selection means for selecting and outputting one signal from a plurality of signals in accordance with a common control signal given from the signal processing device, and the control signal And a plurality of signal state holding means for holding the state of each signal output by the other apparatus, and a plurality of selection means respectively selected from the plurality of signals output by the other apparatus. This signal is input to the signal processing device.

  The signal input device according to the present invention is provided for each selection means, and a plurality of comparison means for comparing one signal to be selected according to the control signal and a signal output by the selection means. And a notification means for notifying the signal processing device when any of the comparison means detects a signal mismatch.

  The signal input device according to the present invention further includes a return means for returning the control signal to the signal processing device.

  Further, an in-vehicle processing system according to the present invention includes a signal input device according to any one of the above-described signals and a signal processing device that performs processing according to a signal input from the signal input device. The signal processing device operates in a low power consumption operation state with low power consumption while the engine of the vehicle is stopped, and in the low power consumption operation state, a plurality of signal input devices The control signal is output so that the selection unit is in a predetermined selection state, and the signal input device is configured to output the control signal while the vehicle engine is stopped when the selection unit is in the predetermined selection state. A signal related to processing performed by the signal processing device is selected and input to the signal processing device.

  In the in-vehicle processing system according to the present invention, the signal relating to the processing performed by the signal processing device while the vehicle engine is stopped includes a signal from a switch relating to locking / unlocking the vehicle door or trunk, or And a signal from a switch for turning on / off the light of the vehicle.

  In the present invention, a signal input device having a plurality of selection means such as a multiplexer is interposed between a signal processing device such as a microcomputer and another device such as a switch or sensor, and signals from other devices are signal input devices. Is selected and input to the signal processing device. Compared with a configuration in which only one selection means is provided by providing a plurality of selection means in the signal input device, the processing time when the selection is sequentially switched and all signals from other devices are input to the signal processing device. Can be shortened. Further, the plurality of selection means provided in the signal input device is configured to select a signal in accordance with a common control signal given from the signal processing device. As a result, the signal processing apparatus does not need to output a plurality of control signals to a plurality of selection means, so that the number of output ports of the signal processing apparatus necessary for selection control can be reduced.

Further, the signal input device includes a signal state holding unit that holds the states of a plurality of signals given from other devices in accordance with a control signal given from the signal processing device. The signal state holding unit can be realized by a latch or a flip-flop, for example, and can hold the signal state according to the edge of the control signal.
Many switches provided in the vehicle are pulled up or pulled down. In the case of such a switch, pull-up or pull-down is performed over a relatively long period before and after the signal processing device captures a signal from the switch, and the power consumption during this period increases. Since the signal input device holds the signal states of these switches, the switch pull-up or pull-down can be stopped thereafter, so that power consumption can be reduced.

  In the present invention, the signal input device includes a plurality of comparison means for comparing one signal to be selected according to the control signal with respect to the input / output of each selection means and the signal output by the selection means. Provided for each selection means. As a result of comparison by a plurality of comparison means, when a signal mismatch is detected by any of the comparison means, it can be determined that an abnormality such as a failure has occurred in any of the selection means of the signal input device. This is notified to the signal processing device. As a result, the signal processing apparatus can cope with not only an abnormality in the apparatus itself but also an abnormality occurring in the signal input apparatus. Further, by comparing the comparison results of the plurality of comparison means into one and notifying the signal processing device, the signal processing required for notification is compared with the configuration in which the comparison results of the plurality of comparison means are respectively notified to the signal processing device. The number of input ports of the device can be reduced.

  In the present invention, the signal input device returns the control signal given from the signal processing device to the signal processing device. As a result, the signal processing device compares the control signal supplied to the signal input device with the returned control signal, and an abnormality occurs in the transmission route of the control signal depending on whether or not they match. It can be determined whether or not.

In the present invention, the signal input device and the signal processing device described above are mounted on a vehicle. The signal processing device operates in a low power consumption operation state such as a sleep mode or a standby mode in order to reduce battery power consumption while the vehicle engine is stopped. In the low power consumption operation state, the signal processing device outputs a control signal so that the selection unit of the signal input device is in a predetermined selection state, and fixes a signal input from the signal input device to the signal processing device. In the low power consumption operation state, the signal processing device does not control the signal input device so as to be in another selected state.
The signal input device receives a plurality of signals from other devices mounted on the vehicle when each of the selection means is in a predetermined selection state when the control signal as described above is given from the signal processing device. Among them, a signal related to processing performed by the signal processing device while the vehicle engine is stopped is selected and input to the signal processing device. As a result, the signal processing device can obtain a necessary signal while the engine of the vehicle is stopped without sequentially switching the signal selection of the signal input device by the control signal. The processing time required for monitoring the input signal can be shortened, and the power consumption can be reduced.
The signal related to the processing performed by the signal processing device while the vehicle engine is stopped is, for example, a signal from a switch related to locking / unlocking of a vehicle door or trunk, or a switch related to turning on / off a vehicle light. These signals are included. However, it is not limited to these.

In the case of the present invention, the number of input ports of the required signal processing device can be reduced by adopting a configuration in which the signal input device selects a signal by a plurality of selection means and inputs it to the signal processing device. By adopting a configuration in which selection of a plurality of selection means is performed according to a common control signal output from the signal processing device, the number of required output ports of the signal processing device can be reduced. Therefore, it is possible to effectively use the input port provided in the signal processing device.
In addition, when the signal input device detects an abnormality in any of the selection means, this is notified to the signal processing device, and the control signal given from the signal processing device is returned to the signal processing device, thereby inputting the signal. Reliability of processing performed by the signal processing device because the signal processing device can cope with abnormality occurring in the device and abnormality occurring in the transmission path of the control signal from the signal processing device to the signal input device. And safety can be improved.

  Further, the signal processing device is configured to output a predetermined control signal in the low power consumption operation state, and when the predetermined control signal is given, the signal input device performs processing performed by the signal processing device while the vehicle engine is stopped. By selecting and outputting such a signal, the signal processing device can shorten the processing time required for monitoring the input signal in the low power consumption operation state, so the power consumption is reduced and the vehicle engine is stopped. The battery can be prevented from running out.

It is a block diagram which shows the structure of the vehicle-mounted processing system which concerns on this invention. It is a block diagram which shows the structure of the input-output control circuit which the signal input device of a vehicle-mounted processing system has. It is a schematic diagram for demonstrating operation | movement of a multiplexer. It is a schematic diagram for demonstrating operation | movement of the vehicle-mounted processing system which concerns on this invention. It is a schematic diagram for demonstrating operation | movement of the vehicle-mounted processing system which concerns on this invention. It is a schematic diagram for demonstrating operation | movement of the vehicle-mounted processing system which concerns on this invention. It is a schematic diagram for demonstrating operation | movement of a state holding part. It is a schematic diagram for demonstrating operation | movement of a state holding part. It is a schematic diagram for demonstrating operation | movement of a state holding part. It is a flowchart which shows the procedure of the process which a signal input device performs.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. FIG. 1 is a block diagram illustrating a configuration of an in-vehicle processing system according to the present invention, and FIG. 2 is a block diagram illustrating a configuration of an input / output control circuit included in a signal input device of the in-vehicle processing system. Although the signal input device has a plurality of input / output control circuits, these have the same configuration, and therefore, only the configuration of one input / output control circuit is shown in FIG.

  The illustrated in-vehicle processing system is configured to be applied to a vehicle body ECU, for example, and includes a microcomputer 1 and a signal input device 2 realized as a custom IC (Integrated Circuit) or the like. The microcomputer 1 and the signal input device 2 are mounted on, for example, a circuit board of the ECU, and their input / output ports are connected via wiring on the circuit board. In the in-vehicle processing system, various switches (SW) arranged at appropriate positions of the vehicle are connected to the signal input device 2 through cables or the like. In the illustrated example, the door lock SW 91, the front (F) wiper SW 92, the F washer SW 93, the headlight SW 94, the rear (R) wiper SW 95, the R washer SW 96, the hazard SW 97, the horn SW 98, the turn light SW 99, and the like are used as the signal input device 2. Connected to (but not limited to).

  The microcomputer 1 includes an arithmetic circuit such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit) and a storage element such as a RAM (Random Access Memory) and a ROM (Read Only Memory). Various arithmetic processes and control processes are performed by executing a program stored in the ROM. For example, when an operation is performed on the door lock SW 91, the microcomputer 1 controls the operation of the door lock mechanism of the vehicle to lock / unlock the door. For example, the microcomputer 1 operates an actuator that drives the front wiper of the vehicle when an operation is performed on the F wiper SW 92.

  The number of switches provided in the vehicle is greater than the number of input ports provided in the microcomputer 1, and all switches cannot be directly connected to the input ports of the microcomputer 1. For this reason, the signal input device 2 is interposed between the microcomputer 1 and the plurality of switches, and the signal input device 2 selects an input signal from each switch and applies it to the microcomputer 1. The signal input device 2 shown in the figure can reduce the number of input ports of the microcomputer 1 to about 1/3 of the number of switches that the microcomputer 1 receives input. That is, 3 × N switches are connected to the signal input device 2, and the signal input device 2 receives N input signals (inputs in FIG. 1 from 3 × N input signals given from these switches). The signals 1 to N) are selected and input to the microcomputer 1.

  Which signal the signal input device 2 selects is determined by the signal input device 2 according to a selection signal (control signal) given from the microcomputer 1. In this example, the selection signal is a 2-bit digital signal. The signal input device 2 has a function of returning the selection signal given from the microcomputer 1 to the microcomputer 1. Thereby, the microcomputer 1 can detect an abnormality such as disconnection of the wiring between the microcomputer 1 for transmitting the selection signal and the signal input device 2. Further, the signal input device 2 has a function of detecting its own abnormality and notifying the microcomputer 1, and gives a 1-bit abnormality detection signal indicating the presence or absence of abnormality to the microcomputer 1. As a result, the microcomputer 1 can cope with an abnormality that has occurred in the signal input device 2.

  The signal input device 2 includes a plurality (N) of input / output control circuits 20, and one return unit 31 and one OR circuit 32, respectively. The return unit 31 is for returning a selection signal given from the microcomputer 1 to the microcomputer 1. For example, the return unit 31 receives an selection signal from the microcomputer 1 and supplies it to a plurality of input / output control circuits 20 in the signal input device 2, and an output buffer that outputs the selection signal output from the input buffer to the microcomputer 1. (The illustration is omitted).

  Each input / output control circuit 20 includes a three-input one-output multiplexer 21, three state holding units 22, and an abnormality detection unit 23. Signals from three switches (signals A to C in FIG. 2) are given to the input / output control circuit 20, and the three signals A to C are respectively input to the state holding unit 22. The state holding unit 22 holds the state (high level / low level) of the signal input according to the selection signal from the microcomputer 1, and the output (held signal state) of each state holding unit 22 is the multiplexer 21. And supplied to the abnormality detection unit 23.

  FIG. 3 is a schematic diagram for explaining the operation of the multiplexer 21. The upper stage shows input / output signals for the multiplexer 21, and the lower stage shows a truth table of the multiplexer 21. The multiplexer 21 is a circuit element that selects and outputs one signal from the three signals A to C in accordance with the value of a 2-bit selection signal (SEL1, SEL2). However, when the selection signals (SEL1, SEL2) = (0, 0), the multiplexer 21 outputs a low level (L) signal regardless of the input signals A to C. The multiplexer 21 selects and outputs the signal B when the selection signals (SEL1, SEL2) = (0, 1), and selects the signal C when the selection signals (SEL1, SEL2) = (1, 0). When the selection signals (SEL1, SEL2) = (1, 1), the signal A is selected and output. The output of the multiplexer 21 is given as an input signal to the microcomputer 1 and also to the abnormality detection unit 23.

  The abnormality detection unit 23 is supplied with the outputs of the three state holding units 22, the output of the multiplexer 21, and the selection signal from the microcomputer 1. The abnormality detection unit 23 compares one signal to be selected by the multiplexer 21 among the outputs of the three state holding units 22 with the output signal of the multiplexer 21 according to the value of the selection signal. For example, when the selection signals (SEL1, SEL2) = (0, 1), the abnormality detection unit 23 compares the signal B to be selected by the multiplexer 21 (the state in which it is held) with the output of the multiplexer 21. To do. As a result of the comparison, when the two signals match, the abnormality detection unit 23 determines that no abnormality has occurred, outputs the abnormality detection signal as a low level, and when the two signals do not match Determines that an abnormality has occurred and outputs the abnormality detection signal as a high level. The abnormality detection signal output from the abnormality detection unit 23 is given to the OR circuit 32.

  The OR circuit 32 is supplied with a 1-bit abnormality detection signal from each of the N input / output control circuits 20 included in the signal input device, that is, N abnormality detection signals. The OR circuit 32 gives a low-level abnormality detection signal to the microcomputer 1 when all the abnormality detection signals given are at a low level. The OR circuit 32 gives a high-level abnormality detection signal to the microcomputer 1 when the given at least one abnormality detection signal is at a high level.

  4 to 6 are schematic diagrams for explaining the operation of the in-vehicle processing system according to the present invention. The in-vehicle processing system according to the present invention has a configuration in which a plurality of multiplexers 21 are provided in the signal input device 2 to select signals, but the configuration of the present invention and a configuration in which only one multiplexer is used to select signals. And compare. For example, when six signals (signal A to signal F) are selected, the configuration of the present invention shown in FIG. 4A uses two three-input one-output multiplexers 21 to transfer the six signals to the microcomputer 1. Select two input signals. Therefore, the microcomputer 1 needs two input ports. In contrast, in the configuration using a 6-input 1-output multiplexer as shown in FIG. 4B, one input signal is selected from 6 signals. In this case, the microcomputer 1 needs one input port.

  In order to acquire all the six signals, the microcomputer 1 has to switch the selection signal and sequentially acquire the six signals. In this case, if the time required to acquire one signal is T, in the configuration of the present invention shown in FIG. 4A, six signals are obtained at time 3T as shown in FIG. It is possible to obtain. On the other hand, in the configuration shown in FIG. 4B, time 6T is required to acquire six signals. From this, if the input port of the microcomputer 1 has a vacancy, the processing time of the microcomputer 1 related to the acquisition of the input signal can be shortened by selecting the signal using as many multiplexers as possible. .

  Further, in the vehicle, the electric power stored in the battery is supplied to the in-vehicle device while the engine is stopped. In order to prevent the battery from running out, it is desired to reduce the power consumption of the in-vehicle device while the vehicle engine is stopped. The microcomputer 1 of the in-vehicle processing system of the present invention has a function of reducing power consumption by shifting the operation to the sleep mode (low power consumption operation state) while the vehicle engine is stopped. In the sleep mode, the microcomputer 1 stops various arithmetic processes and control processes, acquires the input signal intermittently, and wakes up only when it is determined that the process is necessary, such as when there is a change in the input signal. Arithmetic processing, control processing, and the like are performed, and after the processing ends, the mode shifts to the sleep mode. Since current consumption increases when the microcomputer 1 performs processing such as acquisition and determination of an input signal in the sleep mode, it is desirable to perform these processing in as short a time as possible.

  Further, it is not always necessary to operate all the devices mounted on the vehicle while the engine is stopped, and it is often sufficient that only a limited number of devices operate. For this reason, the microcomputer 1 of the in-vehicle processing system does not need to monitor changes in all input signals while the vehicle engine is stopped, and only monitors changes in a limited part of the input signals.

  For example, in FIG. 4, when the engine of the vehicle is stopped, that is, when the microcomputer 1 is operating in the sleep mode, the signals that the microcomputer 1 must monitor are the two signals A and D. In this case, in the configuration of the present invention shown in FIG. 4A, it is possible to acquire both the signal A and the signal D at time T as shown in FIG. On the other hand, in the configuration shown in FIG. 4B, time 2T is required to acquire the signals A and D. Therefore, a signal that the microcomputer 1 needs to acquire in the sleep mode (that is, a signal related to processing performed by the microcomputer 1 while the engine is stopped) is distributed and assigned to the plurality of multiplexers 21 and a predetermined selection is made. By appropriately inputting to the multiplexer 21 so that these signals are selected by signals, the processing time of the microcomputer 1 in the sleep mode can be shortened, and the power consumption of the microcomputer 1 can be reduced. .

  For this reason, in the in-vehicle processing system of the present invention shown in FIG. 1, the door lock SW91, the headlight SW94, and the hazard SW97 that need to monitor the operation state of the switch monitored by the microcomputer 1 while the engine of the vehicle is stopped, In addition to being connected to different input / output control circuits 20, when the selection signals (SEL1, SEL2) = (1, 1) from the microcomputer 1, the signals from these switches are selected and the input signals 1 to N are input to the microcomputer. The connection to the multiplexer 21 is set so as to be input to 1. The F wiper SW92, the F washer SW93, the R wiper SW95, the R washer SW96, the horn SW98, and the turnlight SW99 are switches that the microcomputer 1 does not need to monitor while the vehicle engine is stopped.

  Thereby, the microcomputer 1 only needs to acquire the input signal with the selection signal (SEL1, SEL2) = (1, 1) during the sleep mode, and (SEL1, SEL2) = (0, 1) or (1 , 0), it is not necessary to sequentially acquire the input signal by changing the selection signal, so that the processing time required to acquire the input signal can be shortened.

  7 to 9 are schematic diagrams for explaining the operation of the state holding unit 22. In many cases, a switch disposed in a vehicle is configured to be pulled up to a power source through a resistor. As shown in FIG. 7, for example, three switches (SWA to SWC) are pulled up to a power source by a pull-up circuit 90 via pull-up resistors RA to RC, respectively, and each switch SWA to SWC and resistor RA It is assumed that the voltage between ˜RC is input to the state holding unit 22 of the signal input device 2 as the signals A0 to C0. The pull-up circuit 90 connects / disconnects the pull-up resistors RA to RC and the power source by a switching element such as a FET (Field Effect Transistor) or a bipolar transistor, and operates according to a control signal supplied from the microcomputer 1. ing. When the switches SWA to SWC are pulled up by the pull-up circuit 90, the signals A0 to C0 corresponding to the open switches SWA to SWC are at the high level, and the signals corresponding to the closed switches SWA to SWC are set. The A0 to C0 signals are at a low level.

  The three state holding units 22 to which the signals A0 to C0 are respectively input are realized by, for example, a latch circuit or the like, and correspond to the rising edge of one of the 2-bit selection signals (SEL1) given from the microcomputer 1. Thus, the signal states of the signals A0 to C0 are held (the values of the signals A0 to C0 are latched). In the example shown in FIG. 8, the microcomputer 1 changes the selection signals (SEL1, SEL2) in the order of (0, 0) → (1, 1) → (1, 0) → (0, 1), and the state holding unit In this case, the output of 22 is input to the microcomputer 1 in the order of signal A → signal B → signal C. In this case, since SEL1 rises when the selection signal (SEL1, SEL2) changes from (0, 0) to (1, 1), the state holding unit 22 holds the signal states of the signals A0 to C0.

  Thereafter, the multiplexer 21 inputs the signals held in the state holding unit 22 to the microcomputer 1 in the order of signal A → signal B → signal C in accordance with the change of the selection signal. Since the signal selected by the multiplexer 21 is a signal held at the rising edge of SEL1, the state of the switches SWA to SWC changes and the signal A0 to the signal C0 input to the state holding unit 22 changes. However, the states of the signals A to C output from the multiplexer 21 do not change during the output.

  As shown in FIG. 7, when the switches SWA to SWC are pulled up by the pull-up circuit 90, current flows when the switches SWA to SWC are closed. For this reason, the microcomputer 1 operates the pull-up circuit 90 only when it is necessary to determine the states of the switches SWA to SWC (when it is necessary to acquire an input signal from the signal input device 2). Pull up the SWC. A correct signal indicating the operation state cannot be obtained from the switches SWA to SWC that are not pulled up.

  If the signal input device 2 does not have the state holding unit 22, the microcomputer 1 starts the pull-up by the pull-up circuit 90, and continues to pull up the switches SWA to SWC after the pull-up voltage rises and stabilizes. In this state, it is necessary to sequentially acquire input signals from the signal input device 2 (see FIG. 9A). On the other hand, in the configuration of the present embodiment in which the signal input device 2 includes the state holding unit 22, after the pull-up voltage is stabilized and the signal holding state is held in the state holding unit 22, the microcomputer 1 performs the pull-up circuit 90. The pull-up due to can be stopped, and the input signals from the signal input device 2 can be acquired in order (see FIG. 9B). Therefore, by providing the state holding unit 22 in the signal input device 2, the pull-up time of the switches SWA to SWC can be shortened, and the power consumption associated with the pull-up can be reduced.

  FIG. 10 is a flowchart showing a procedure of processing performed by the signal input device 2. The procedure of processing is shown by taking the case where the signal input device 2 has the configuration shown in FIG. 7 as an example. The signal input device 2 determines the presence or absence of a rising edge of one of the selection signals (SEL1) given from the microcomputer 1 (step S1). If SEL1 is a rising edge (S1: YES), the signal is switched by the state holding unit 22 The state of signals from SWA to SWC is held (step S2), and when SEL1 is not a rising edge (S1: NO), the state is not held.

  The signal input device 2 determines whether the selection signals (SEL1, SEL2) from the microcomputer 1 are (1, 1) (step S3), and the selection signals (SEL1, SEL2) are (1, 1). If not (S3: NO), it is determined whether or not the selection signals (SEL1, SEL2) are (1, 0) (step S4), and if the selection signals (SEL1, SEL2) are not (1, 0) ( S4: NO), it is determined whether or not the selection signals (SEL1, SEL2) are (0, 1) (step S5). When the selection signals (SEL1, SEL2) are (1, 1) (S3: YES), the signal input device 2 selects the signal A (step S6), and the selection signals (SEL1, SEL2) are (1, 0). (S4: YES), the signal B is selected (step S7), and if the selection signals (SEL1, SEL2) are (0, 1) (S5: YES), the signal C is selected (step S8). When the selection signal (SEL1, SEL2) is not (0, 1) (S5: NO), that is, when the selection signal (SEL1, SEL2) is (0, 0), the signal input device 2 ~ Outputs a predetermined value such as L (low level) without selecting the signal C.

  The signal input device 2 also includes one signal to be selected according to the value of the selection signal (SEL1, SEL2) among the three inputs (signal A0 to signal C0) to the multiplexer 21, and the output signal of the multiplexer 21. Are determined by the abnormality detection unit 23 (step S9). That is, when the selection signal (SEL1, SEL2) = (1, 1), the signal input device 2 determines whether or not the signal A0 matches the output of the multiplexer 21, and the selection signal (SEL1, SEL2) = In the case of (1, 0), it is determined whether or not the signal B0 and the output of the multiplexer 21 match. When the selection signal (SEL1, SEL2) = (0, 1), the signal C0 and the multiplexer 21 It is determined whether or not the output matches. When the input and output match (S9: YES), the signal input device 2 outputs the abnormality detection signal as L (low level) (step S10), and when the input and output do not match (S9: NO), the abnormality detection signal Is output as H (high level) (step S11).

  The signal input device 2 repeats (or always) performs the processing shown in FIG. 10 while power from the vehicle battery is supplied.

  In the in-vehicle signal processing system having the above configuration, the signal input device 2 including a plurality of input / output control circuits 20 having the multiplexer 21 is interposed between the microcomputer 1 and a plurality of switches such as the door lock SW 91 and the F wiper SW 92. The signal input device 2 selects and inputs the signals from the plurality of switches to the microcomputer 1, so that the microcomputer 1 has all the selections compared to the configuration in which a plurality of signals are selected by one multiplexer. The time required to acquire the input signal can be shortened. The plurality of multiplexers 21 included in the signal input device 2 are configured to select signals according to a common selection signal from the microcomputer 1, so that the microcomputer 1 outputs individual selection signals to each multiplexer 21. Therefore, the number of output ports of the microcomputer 1 necessary for controlling the signal input device 2 can be reduced.

  In addition, each input / output control circuit 20 of the signal input device 2 detects an abnormality by comparing the signal to be selected according to the control signal from the microcomputer 1 with the signal selected by the multiplexer 21. The microcomputer 1 determines whether or not there is an abnormality in the signal input device 2 by providing each of the sections 23 and configured to notify the microcomputer 1 when an abnormality is detected by any abnormality detection unit 23. It is possible to take measures such as stopping the processing when an abnormality occurs. Further, the signal input device 2 is configured so that the selection signal from the microcomputer 1 is returned to the microcomputer 1 by the return unit 31, so that the microcomputer 1 selects the selection signal returned to the signal input device 2 by itself. It is possible to determine whether or not an abnormality has occurred in the transmission path of the selection signal or the like according to whether or not they match with each other.

  In addition, the signal input device 2 is configured to hold the states of signals given from a plurality of switches by the state holding unit 22 so as to perform pull-up when these switches are to be pulled up. The time can be shortened and the amount of power consumption accompanying the pull-up of the switch can be reduced.

In addition, the microcomputer 1 operates in the sleep mode while the vehicle engine is stopped, and the microcomputer 1 outputs a predetermined selection signal in the sleep mode to acquire an input signal from the signal input device 2. For example, the microcomputer 1 outputs a selection signal (SEL1, SEL2) = (1, 1) in the sleep mode, and acquires and processes a signal (signal A) input from the signal input device 2 in response thereto ( However, the microcomputer 1 performs a process of changing the selection signal from (0, 0) to (1, 1) in order to cause the state holding unit 23 to hold the signal state.
In the signal input device 2, in response to a selection signal output from the microcomputer 1 in the sleep mode, signals from the door lock SW91, the headlight SW94, the hazard SW97, etc., which are targets of processing performed by the microcomputer 1 while the engine of the vehicle is stopped, are received. Each signal input to the multiplexer 21 is set so as to be selected.
Thus, the microcomputer 1 can acquire an input signal necessary when the engine of the vehicle is stopped without sequentially switching the selection signal in the sleep mode. Therefore, the possession time required for the microcomputer 1 to acquire the input signal in the sleep mode can be shortened, and the power consumption can be reduced.

  In the present embodiment, the signal input device 2 selects and inputs the signals from various switches such as the door lock SW 91, the F wiper SW 92, and the F washer SW 93 to the microcomputer 1, but the present invention is not limited thereto. Instead, the signal input device 2 may select and input signals from other devices such as various sensors to the microcomputer 1. The switch illustrated in FIG. 1 is an example, and the signal input device 2 may select a signal from a switch other than that illustrated. The switches required by the microcomputer 1 when the vehicle engine is stopped include, for example, a switch for locking / unlocking each door of the vehicle, a switch for locking / unlocking the trunk, and a switch for turning on / off the hazard. There are switches for turning on / off the headlight, small light and fog light, or a switch (dima switch) for switching the irradiation direction of the headlight. Further, as a switch that the microcomputer 1 does not need when the vehicle engine is stopped, for example, a switch for operating a direction indicator (turn light switch), a switch for operating a front wiper or a rear wiper, or a horn. There are switches.

  In addition, the multiplexer 21 included in the signal input device 2 has three inputs and one output, but is not limited thereto, and may be a multiplexer with two inputs or four inputs or more. The configuration of the multiplexer 21 of the signal input device 2 can be appropriately set according to the number of input ports of the microcomputer 1, and the configuration of the selection signal can be determined according to the configuration of the multiplexer 21.

1 Microcomputer (signal processing equipment)
2 Signal input device 20 Input / output control circuit 21 Multiplexer (selection means)
22 State holding unit (signal state holding means)
23 Abnormality detection unit (comparison means)
31 Return part (return means)
32 OR circuit (notification means)
91 Door lock SW (other devices)
92 F Wiper SW (Other devices)
93 F washer SW (other devices)
94 Headlight SW (other devices)
95 R wiper SW (other devices)
96 R washer SW (other devices)
97 Hazard SW (Other devices)
98 Horn SW (other devices)
99 Turn Light SW (Other devices)

Claims (5)

A signal input that is interposed between a signal processing device and one or more other devices that output signals to be input to the signal processing device, and that inputs a plurality of signals output by the other devices to the signal processing device. In the device
A plurality of selection means for selecting and outputting one signal from a plurality of signals according to a common control signal given from the signal processing device;
A plurality of signal state holding means for holding the state of each signal output by the other device in response to the control signal;
A signal input device, wherein a plurality of signals selected by a plurality of selection means among a plurality of signals output from the other device are input to the signal processing device. A plurality of comparison means provided for each selection means, for comparing one signal to be selected according to the control signal and a signal output from the selection means;
The signal input device according to claim 1, further comprising: a notification unit configured to notify the signal processing device when a signal mismatch is detected by any of the comparison units. The signal input device according to claim 1, further comprising return means for returning the control signal to the signal processing device. An in-vehicle processing system that is mounted on a vehicle and includes a signal input device according to any one of claims 1 to 3 and a signal processing device that performs processing according to a signal input from the signal input device. There,
The signal processing device includes:
Operates in a low power consumption operating state with low power consumption while the vehicle engine is stopped,
In the low power consumption operation state, the control signal is output so that the plurality of selection units of the signal input device are in a predetermined selection state,
The signal input device is:
When the selection means is in the predetermined selection state, a signal related to processing performed by the signal processing device while the engine of the vehicle is stopped is selected and input to the signal processing device. In-vehicle processing system. The signal related to the processing performed by the signal processing device while the vehicle engine is stopped includes a signal from a switch for locking / unlocking the door or trunk of the vehicle, or on / off of the light of the vehicle The in-vehicle processing system according to claim 4, further comprising a signal from a switch.

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