JP4272772B2 - Reset control device and control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a CPU reset apparatus and method when a CPU software program runs away.
[0002]
[Prior art]
Conventionally, when a CPU software program runs out of control, a modem, which is a connected communication device, has an automatic response function, and the modem receives an incoming call from a telephone line and sends a predetermined reset data. However, the data is received and analyzed by a hard logic circuit not controlled by the CPU, and a reset signal is sent to the CPU. FIG. 2 shows a configuration example of a conventional reset circuit. In FIG. 2, the modem 203 is connected to the external device 201 via the telephone line 202. The CPU 204 exchanges data with the external device 201 via the modem 203. When there is an incoming call on the telephone line 202, the ringing signal is pulsed by the ringing signal detection circuit 206 and sent to the modem 203, and the modem 203 automatically answers. Data from the external device 201 is demodulated by the modem 203 and received by the CPU 204. If the watchdog timer 205 is not reset from the CPU 204 within a predetermined time, the built-in timer overflows and no clear signal is sent to the shift register 208. When the software program of the CPU 204 is operating normally, the watchdog timer 205 is reset every predetermined time, so that a clear signal is transmitted. The shift register 208 accumulates data from the modem in synchronization with the clock of the transmitter 207 only when there is no clear signal from the watchdog timer 205, and outputs it to the Q0 to Q7 terminals of the comparison circuit 209. On the other hand, the switch circuit 210 outputs data determined by turning on and off the eight switches to the P0 to P7 terminals of the comparison circuit 209. When the data from Q0 to Q7 is equal to the data from P0 to P7, the comparison circuit 209 sends a reset signal to the reset terminal of the CPU 204 to reset the CPU 204 in hardware.
[0003]
If the software program of the CPU 204 runs out of control, data cannot be transmitted / received via the modem 203 to / from the external device, and the external device sends the same reset data as the data set by the switch circuit 210 to the modem. The reset data is demodulated by the modem and enters the DATA terminal of the shift register 208. Since the CPU 204 runs out of control, the watchdog timer 205 is not reset, the timer overflows, and a clear signal is not sent to the shift register 208. Therefore, reset data is taken into the shift register 208 and compared with the setting data of the switch circuit 210 by the comparison circuit 209. Since this is the same data, the comparison circuit 209 sends the output to the reset terminal of the CPU 204, and the CPU 204 is reset in hardware. In the past, soft program runaway was reset in this way.
[0004]
[Problems to be solved by the invention]
However, such a reset circuit requires an oscillator, a shift register, a switch circuit, a comparison circuit, etc. as a hard logic circuit for analyzing data received on the telephone line, and the circuit configuration is complicated, the number of parts, The area occupied by the base increased, which was a factor in increasing the cost of the equipment.
[0005]
An object of the present invention is to provide a reset control apparatus and method capable of outputting a CPU reset signal when a CPU soft program runaway occurs with a simple circuit configuration.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides at least a communication means connected to a telephone line and a device having a CPU that is operated by a software program and is reset by a reset signal.
A clear signal generating circuit that sends a clear signal when the CPU is operating normally, and stops sending a clear signal when the CPU is not operating normally; and a call signal detecting circuit for the telephone line; ,
A counting circuit that counts the number of times a call signal is called only when transmission of the clear signal from the clear signal generation circuit is stopped;
There is provided a reset control device comprising a reset signal sending circuit for sending a reset signal to the CPU when a count value of the counting circuit reaches a predetermined fixed number.
[0007]
Further, the present invention is a method of resetting the CPU when a CPU operating by a software program having a communication device connected to a telephone line does not perform a normal operation,
The function of counting the number of times a call signal is sent from a telephone office when an incoming call is received on the telephone line, and the function of counting the number of times the call signal is sent when the CPU is operating normally. If the CPU is not operating normally, the number of times the call signal is sent is counted, and the CPU is reset when the count reaches a predetermined number. A reset control method is provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a block diagram showing a configuration example of a reset control device according to the present invention, which is an example incorporated in a relay amplification device for a mobile phone. The relay amplification device 100 is a device that enables the use of a mobile station (cell phone, pager, etc.) 121 in a place where radio waves do not reach, such as an underground shopping center, a tunnel, and the like from the base station device 122 installed outdoors. A radio signal is received by the receiving device 101 and transmitted to the mobile station 121 via the master station device 106, the optical cable 124, and the slave station device 115. The receiving device 101 is a device that transmits a radio signal received by the antenna 102 to the master station device 106 through the filter 103, the optical modulator 104, and the optical circulator 105.
[0009]
The antenna 102 receives a radio signal from the base station 122, extracts only a radio signal having a desired frequency from the radio signal received by the filter 103, and transmits the radio signal to the optical modulator 104. The optical modulator 104 modulates the intensity of incident light from the optical circulator 105 by electricity and reflects the incident light. The optical circulator 105 separates the incident light from the electrical / optical converter 107 and the light reflected by the optical modulator 104, and transmits this optical signal to the optical distributor 108 of the master station device 106. The electrical / optical converter 107 supplies direct current light to the receiving apparatus 101, and includes a laser diode and a drive circuit thereof. The optical distributor 108 distributes the optical signal subjected to the optical intensity modulation by the receiving unit 101 and transmits the optical signal to the plurality of slave station devices 115, 115.
[0010]
The control unit 109 performs state monitoring and various controls of the master station device 106. A CPU 110, a modem 111, a ROM 112, and a RAM 113 are provided as main components. Further, it is connected to the monitoring station 123, and executes various commands from the monitoring station 123 and notifies the monitoring station 123 of the status of the master station device 106. The CPU 110 monitors and controls the master station device, controls the input / output of the modem 111, transmits / receives data to / from the monitoring station 123 via the modem 111, reads the system operation program stored in the ROM 112, and reads / writes processing data to / from the RAM 113. Do. The modem 111 is connected to the monitoring station 123 via a telephone line, and exchanges data between the monitoring station 123 and the CPU 109. The ROM 112 uses a readable / writable flash memory and incorporates an operation program for the CPU 201. Normally used as a read-only memory. The RAM 113 temporarily stores data transmitted by the modem 111, received data, and data being processed by the CPU 110. The power supply 114 supplies power to each unit of the master station device 109.
[0011]
The reset control device 130 hardware resets the CPU 110 by a reset signal from the reset signal generation device 134. The call signal detection circuit 131 is connected to a telephone line and detects a call signal sent from a switching station when an incoming call is received from a monitoring station. Counts the number of times the sent call signal has been sent. The clear signal generation circuit 133 is controlled by the CPU 110 and, when the CPU 110 is operating normally, sends a clear signal to the counting circuit 132 to clear the count of the calling signal in the counting circuit 132 and prevent it from being counted. Yes. When the result of counting the paging signal reaches a predetermined number of times, the counting circuit 132 drives the reset signal generating circuit 134 and sends the reset signal to the CPU 110.
[0012]
The optical cable 124 is an optical fiber cable that transmits a radio signal converted into an optical signal to the slave station device 115 located away from the master station device. The slave station device 115 is installed in a place where a radio signal directly transmitted from the base station 122 does not reach (in a tunnel, in a building, an underground shopping area, etc.), and receives the radio signal received from the master station device 106 via the optical cable 124. Amplify and send to mobile station 121. There are usually a plurality of slave station devices 115 for one master station device. The radio signal received from the optical / electrical converter 116 is amplified by the amplifier 117 and transmitted from the antenna 120 to the hollow space. The control unit 118 monitors the state of the slave station device 115 and performs various controls. The power source 119 supplies power to each unit of the slave station device 115. The mobile station 121 is a mobile phone or pager used by a general user, and receives a radio signal by an antenna 125. The base station 122 is a wireless base station device for a cellular phone or pager installed by a business operator. The monitoring station 123 is a device that collectively manages a plurality of master station devices in the central management room of the business operator.
[0013]
Next, the operation of the reset control device 130 will be described in detail based on the operation flow of FIG. When the software program of the CPU 110 of the control unit 109 is operating normally (NO in STEP 10), the CPU 110 periodically sends a signal to the clear signal generating device 133 of the reset control device 130, and from the clear signal generating device 133, A count clear signal is sent to the count circuit 132 (STEP 12). The count clear signal from the clear generation signal device 133 is cleared to zero even when counting is started by the counting circuit 132 (STEP 13). At this time, if there is an incoming call from the monitoring station 123 (YES in STEP 14), the modem 111 notifies the CPU 110 that the incoming call has been received, and the CPU 110 responds with the modem 111 (STEP 15). Start sending and receiving. That is, the modem 111 is set so that it responds under the control of the CPU 110 and the modem 111 does not automatically respond. A normal modem has this function. If there is no incoming call from the monitoring station 123 in STEP 14 (NO in STEP 14), the process returns to the beginning. If the software program of the CPU 110 runs away due to noise or the like and does not operate normally (YES in STEP 10), the signal for controlling the clear signal generator 133 from the CPU 110 stops, so the clear signal generator 133 is sent to the counting circuit 132. Transmission of the count clear signal is stopped (STEP 11).
[0014]
The monitoring station 123 transmits / receives data to / from the CPU 110 via the modem 111. However, if the software program of the CPU 110 runs out of control, the data cannot be transmitted / received to / from the CPU 110. When the monitoring station 123 becomes unable to transmit and receive data, it temporarily disconnects the telephone line with the modem 111 and makes another incoming call to the modem 111 via the telephone line (YES in STEP 17). A call signal for an incoming call on the telephone line reaches the modem 111. However, if the CPU 110 soft program runs away, the modem 111 does not respond, so the call signal from the telephone line continues to be sent. This calling signal is pulsed by the calling signal detection circuit 131 (STEP 18) and added to the counting circuit 132 (STEP 19). The counting circuit 132 counts this pulse, and when the count value reaches a predetermined constant value (YES in STEP 20), the reset signal generating circuit 134 is driven (STEP 21), and the reset signal is sent to the CPU 110 (STEP 22). ) The CPU 110 is reset by hardware (STEP 23), and the runaway of the software program stops. If the runaway of the CPU 110 is stopped and the software program performs a normal operation, the flow returns to the NO flow of STEP 10, the count clear signal is sent from the clear signal generator 133 (STEP 12), and the count circuit is cleared (STEP 13). Since the incoming call is being received (YES in STEP 14), a response is received from the modem 111 (STEP 15), and data is transmitted and received between the monitoring station 123 and the CPU 110 (STEP 16). When the CPU 110 is operating normally with the software program, the clear signal generation circuit 133 sends a clear signal to the counting circuit 132 (STEP 12), and the counting circuit 132 clears the count value (STEP 13). The count value at (1) does not reach a predetermined constant value (NO at STEP 20). For this reason, when the count clear signal from the clear signal generator 133 is sent continuously or in a pulse manner, the count circuit 132 counts the calling signal for the count clear signal sending interval. However, it is necessary to make it shorter than the time until a certain value is reached.
[0015]
Next, a specific circuit configuration example of the reset control device 109 is shown in FIG. In this example, a call signal detection circuit 306 corresponds to the call signal detection circuit 131 in FIG. 1, and a watchdog timer 305 corresponds to the clear signal generator 133. The counting circuit 132 is constituted by a counter 307 and uses its output as it is as a reset signal for the CPU, so the reset signal generation circuit 134 is omitted and simplified. Further, the modem 111 in FIG. 1 has a configuration in which the modem 111 itself detects that there is an incoming call, but in FIG. 3, it is configured to know that there has been an incoming call with the pulsed output of the call signal detection circuit 306. . The operation of FIG. 3 will be described below. When the CPU 304 in FIG. 3 is operating normally, a timer clear signal is periodically sent from the CPU 304 to the watchdog timer 305, so that the built-in timer of the watchdog timer 305 does not overflow and is cleared to the counter 307. A signal is being sent out. Therefore, the counter 307 does not count even if there is an input. An external monitoring device (not shown) exchanges data with the CPU 304 via the telephone line 201 and the modem 302. The call signal detection circuit 306 pulses the call signal when there is an incoming call on the telephone line, and sends it to the modem 302 and the counter 307. The modem 302 does not automatically answer even when an incoming call is received, but selects a mode in which the fact that a call signal has been detected is sent to the CPU 304 and responds under the control of the CPU 304. A normal modem has such a mode.
[0016]
If the software program of the CPU 304 runs out of control while the external monitoring station is sending / receiving data to / from the CPU 304, data transmission / reception becomes impossible. Therefore, the monitoring station temporarily disconnects the telephone line 302 and resets the telephone line 302 to reset the CPU 304. The incoming call signal is pulsed by the incoming call signal detection circuit 306. That is, a 1-second call and 2-second disconnection signal is added to the L1 and L2 terminals of the telephone line 302 as shown by the waveform 401 in FIG. This ringing signal is rectified in both waves by the diode bridge 308, and becomes a waveform 402 in FIG. This waveform is isolated by the photocoupler 309 from the DC potential, smoothed by the capacitor, and becomes a waveform 403 in FIG. This waveform is pulsed by the Schmitt trigger circuit 310, shaped at a point C as shown by the waveform 404 in FIG. 4, and applied to the modem 302 and the CLK terminal of the counter 307. Since the CPU 304 is running out of control, the modem 302 cannot respond. The pulsed ringing signal continues to be applied to the counter 307. On the other hand, since the clear signal from the watchdog timer 305 is stopped, the pulsed calling signal starts to be counted by the counter 307. When the counter 307 counts to a preset value, it sends an output pulse to the output terminal. For example, if the set value of the counter 307 is set to 10, an output pulse is sent out when the calling signal is applied 10 times. Since this is connected to the reset terminal of the CPU 304, the CPU 304 is reset by hardware, the runaway of the software program is stopped, and normal operation is restored. If the software program of the CPU 304 becomes normal, the timer of the watchdog timer 305 is reset, so that the clear signal is sent from the watchdog timer 305 to the counter 307, and the counter 307 does not count the calling signal, The reset signal is not output. In addition, since a response is made from the modem 302, data can be transmitted to and received from the monitoring device.
[0017]
As described above in detail, according to the present invention, even if the CPU software program runs out of control, it is possible to reset the CPU from a remote monitoring device and restore control. The reset control device of the present invention shown in FIG. 3 has a much simpler circuit than the conventional reset control circuit shown in FIG. That is, the functions performed by the shift register, comparison circuit, switch circuit, and transmitter in FIG. 2 are realized by a single counter in FIG.
[0018]
【The invention's effect】
The present invention has the following advantages.
(1) Since the conventional reset control circuit is greatly simplified, the number of parts and the area occupied by the substrate can be reduced, and a highly economical device can be realized.
(2) Since the CPU reset signal is generated by counting the number of call signals, it is not necessary to send a reset signal as data from the monitoring device.
[Brief description of the drawings]
FIG. 1 is a block diagram when the reset control device of the present invention is applied to a portable radio relay amplification device.
FIG. 2 is an example of a conventional reset control circuit.
FIG. 3 is a specific circuit configuration example of the reset control device of the present invention.
FIG. 4 is a diagram of signal waveforms in a call signal detection circuit.
FIG. 5 is an operation flow of the reset control device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Portable radio | wireless relay amplification apparatus 101 Reception apparatus 106 Master station apparatus 109 Control part 110 CPU
111 modem 115 slave station device 121 mobile station 122 base station 123 monitoring station 124 optical cable 130 reset control device 131 paging signal detection circuit 132 counting circuit 133 clear signal generation circuit 134 reset signal generation circuit 201 external device 202 and 302 telephone lines 203 and 303 Modem 204, 304 CPU
206, 306 Call signal detection circuit 207 Oscillator 208 Shift register 209 Comparison circuit 210 Switch circuit 301 Monitoring device 307 Counter 308 Diode bridge 309 Photocoupler 310 Schmitt trigger

Claims (2)

Communication means for connecting to at least a telephone line, operated by software programs, a reset controller for resetting the CPU of the device having a CPU which is reset by a reset signal,
A counting circuit for counting the number of calls of the telephone line calling signal;
A reset signal sending circuit count of the regimen counting circuit and becomes constant number of predetermined sending the reset signal to said CPU,
When the CPU is operating normally, a clear signal is sent to clear the count value of the counting circuit at an interval shorter than the counting circuit counts the constant value, and when the CPU is abnormal, A reset control device comprising: a clear signal generation circuit for stopping transmission of a clear signal . A method of resetting the CPU when a CPU operating by a software program has a communication device connected to a telephone line and does not perform a normal operation,
Has the function of counting the call out the number of times of the paging signal transmitted from the central office for incoming calls to the telephone line,
When the CPU is performing a normal operation, it clears the count value of the call out number by the function at intervals shorter than the features certain number counting predetermined the invocation count, the CPU If it is abnormal, a reset control method characterized in that the clearing of the count value of the call count by the function stop, the counted value by the function to reset the CPU to reach the certain number .

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