JPS645779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reset method in a control system such as a car telephone having a plurality of control circuits.

In such a control system, as will be described later, there is no effective means for correctly resetting the control circuit to the initial value when the other control circuit malfunctions.

The present invention solves the conventional drawbacks, and when one control circuit detects an abnormal operation of the other control circuit, one control circuit forcibly sets the other control circuit to the initial set, To provide a reset method that quickly restores normal operation.

The present invention will be explained in detail below with reference to the drawings.

First, as an example of a control system to which the present invention is applied,
The car telephone device will be explained.

Conventionally, among car telephones, dial-in handset type telephones (hereinafter referred to as D/H telephones), which have a dial, display, etc. in the handset, have a control circuit built into the telephone body to control the entire telephone and Some devices use a configuration in which a dial and display are built into the handset, and the dial and display inside the handset are controlled from the control circuit of the telephone main body, but this increases the number of core wires in the cable connecting the handset and the telephone main body, The connection cable has become so thick that it is no longer practical.

Therefore, in order to reduce the number of core wires in the connecting cable, an example of a proposed configuration is shown in FIG. 1, in which control circuits are provided in both the handset and the telephone body, and data is transmitted between them. Here, 100 is the radio unit of the car phone, 200 is the phone body, and 30
0 is handset. The radio unit 100 includes
An antenna 101 is provided for making calls to a base station, and signals are transmitted between the radio section 100 and the telephone main body 200 through an audio system consisting of a transmitting signal line 102 and a receiving signal line 103, and a digital signal line 104. mutual transmission. Further, power is supplied to the radio unit 100 from a car battery (not shown), and is supplied to the telephone main body 200 and the handset 300 through a power line 105. Phone Honmae 20
0 and the handset 300, 201 and 301 are first and second control circuits that perform respective control, 202 and 304 are first and second signal transmission circuits that convert parallel signals into serial signals and transmit them. 203 and 305 are transmission completion detection circuits that detect that the signal transmission circuit 202 or 304 has completed transmission of a series of signals; 204 and 302 are first and second circuits that receive serial signals and convert them into parallel signals; Signal receiving circuits 205 and 303 are reception completion detection circuits 206 that detect that the signal receiving circuit 204 or 302 has completed receiving a series of signals.
3 is a repetition timer that defines the repetition time of signal transmission between the telephone main body 200 and the handset 300; 306 is an input means such as a keyboard; 307 is a display such as a 7-segment; 308 is a power supply circuit;
09 is a transmitter, and 310 is a receiver.

Signal transmission between the telephone main body 200 and the handset 300 will be explained. First, telephone 200
In order to send a signal to the handset 300 (for example, a signal to the display 307) from the control circuit 201 of the telephone body 200, the control circuit 70
1, a series of data is set in the signal sending circuit 202 according to a prescribed format, and a repeat timer 206 is activated. Signal transmission circuit 2
The data set to 02 is converted from a parallel signal to a serial signal, and the signals are sequentially sent to the signal receiving circuit 302. When the signal transmission circuit 202 detects that data transmission has been completed, the transmission completion detection circuit 203 notifies the control circuit 201 of transmission completion, and
The control circuit 201 switches the mode from the data transmission mode to the reception mode and waits for data reception.

On the other hand, on the handset 300 side, the telephone body 20
The signal from the signal transmission circuit 202 of 0 is received by the signal reception circuit 302, converted into a parallel signal, and notified to the control circuit 301. When the reception completion detection circuit 303 detects that the reception of a series of data has been completed in the signal reception circuit 302, it notifies the control circuit 301 that the reception has been completed. When the control circuit 301 detects that data reception has been completed, it performs an error check on the data received by the signal reception circuit 302, for example, by a parity check, and if there is no error,
The data is imported and necessary processing is performed, such as displaying it on a display. Thereafter, the control circuit 301 reads data from the input means 306 and sets the data in the signal transmitting circuit 304 in accordance with a prescribed format. Signal transmission circuit 304
converts the parallel signal to a serial signal and sends it to the phone body 2.
Data is sent to 00. When the transmission is completed, the transmission completion detection circuit 305 detects the completion of the transmission,
The control circuit 301 is notified, the control circuit 301 completes the transmission operation, and waits to receive the next data.

On the other hand, in the telephone main body 200, the signal receiving circuit 204 receives the data signal and transfers it to the control circuit 201. When the reception completion detection circuit 205 detects the completion of a series of data reception, the reception completion detection circuit 205 detects the completion of reception by the control circuit 2.
Notify 01. The control circuit 201 checks the received data for errors, takes in the data if there are no errors, and sends the necessary processing, ie, keyboard data, to the radio section 100 through the digital signal line 104.

The radio unit 100 performs necessary processing according to the key information.

In the telephone body 200, a repeat timer 206
Wait for the time to come up and set the handset again at 30.
Resume sending data to 0.

By repeating the above operations, data is transferred between the radio section 100, the telephone main body 200, and the handset 300. Also, regarding audio signals,
The transmitter 309 and the radio unit 100 are connected to the transmitting signal line 1
02, the radio unit 100 and the handset can communicate through a reception signal line 103.

In the normal case, as described above, abnormalities may occur in the operation of the control circuit 201 or 301 due to noise or the like. In this case, the control circuit 201 or 301 may run out of control, and subsequent operation cannot be guaranteed. In order to detect an abnormality in such a state, for example, a watchdog timer corresponding to the control circuit is used. Once this watchdog timer starts operating, if the watchdog timer is not restarted within a certain period of time, it will forcefully notify the control circuit 201 or 301 that an abnormality has occurred after a certain period of time has elapsed, and the control circuit 201 or 3
01 explains how to reset all conditions to the initial state and start operation again, and how to use the watchdog.
There is a method of forcibly resetting the entire system after the timer has elapsed for a certain period of time and restarting the system. However, with these methods, although it is possible to detect abnormalities in the control circuit 201 or 301,
For example, control circuit 301 in handset 300
Even if an abnormality occurs and data cannot be transferred normally, the control circuit may not be able to detect it. In this case, even if the control circuit 201 on the phone main body 200 side may be able to detect the abnormal operation, the abnormal operation of the control circuit 301 merely waits for it to become normal, and the control circuit 301 is forcibly detected. It was impossible to quickly return to the normal state by performing a recovery process to reset to the initial state.

FIG. 2 shows an embodiment of the present invention to eliminate the above-mentioned drawbacks, and the same components as those in FIG. 1 are given the same numbers. The normal operation is almost the same as the configuration shown in Figure 1, but
When the telephone main body 200 normally receives data from the handset 300, the reception completion detection circuit 205 notifies the control circuit 201, processes the received data, and then repeats the timer 2.
When the operation 06 is completed, the gate circuit 207 checks whether the reception of the immediately preceding data has been completed. If the reception has not been completed, the gate circuit 207 outputs a signal and the gate circuit 208
, and the count value of the error counter 209 is advanced. If reception is normal, no output is output from the gate circuit 207, so the error counter 209 will not count up. Then the control circuit 20
1 checks the value of the error count, and if the value is above a certain value, the control circuit 201 causes the power supply control circuit 211 to stop supplying power to the handset side for a certain period of time, and then turn it on again after a certain period of time. This operation causes the power supply circuit 3 on the handset 300 side to
When the control circuit 308 detects the power supply state and detects a power outage, the control circuit 308 detects the power supply state and, when the power off is detected, resets the control circuit 301. In this way, by turning on the power again, the control circuit 301 can be completely returned to its initial state. Therefore, due to noise etc., the state holding circuit in the control circuit, such as a flip
Since the flop can be initially set, the control circuit 30
Even errors that cannot be detected in the control circuit 201 can be detected by the control circuit 201, and the control circuit 301 can be reset to the initial state.

On the other hand, when data is received from the handset 300 and the reception completion detection circuit 205 notifies the control circuit 201 of reception completion, the control circuit 201 checks the received data and if an error such as a parity error is detected. outputs a signal to the signal line 208a and advances the count value of the error counter 209 through the gate circuit 208. After that, when the repetition timer 206 times up, the gate circuit 207 receives input from the repetition timer 206 side, but there is no input from the reception completion detection circuit 205, so no output is output, and the error counter 209 does not count up. . At the same time, control circuit 2
01 checks the value of the error counter 209, and if the value of the error counter 206 is above a certain level,
As described above, processing such as power-off for a certain period of time is performed on the power supply control circuit 211, so further explanation will be omitted.

Regarding resetting the error counter 209,
If the control circuit 201 checks the received data and receives the data normally, or if the control circuit 201 detects that the error counter 209 is greater than or equal to the specified value, the operation is as shown in FIG. The error counter 209 can be reset by the control circuit 201 according to the flow.

In another embodiment, an error counter timer (not shown) is provided, and when the control circuit 201 detects that the error counter 209 is equal to or greater than a specified value after a certain period of time has elapsed, the control circuit performs an operation flow as shown in FIG. Error counter 20 from 201
9 may be reset.

In the above explanation, a method is used in which the power is cut off when resetting the control circuit 301 on the handset 300 side from the telephone main body 200 side. It goes without saying that a configuration may be used in which the data is directly reset.

Further, although error detection is performed only on the telephone main body 200 side, abnormality detection means is similarly provided on the handset 300 side, and the error detection means is similarly provided on the handset 300 side.
Needless to say, it is also possible to add a configuration for resetting the control circuit 201 on the telephone main body 200 side from the telephone main body 200 side.

As explained above, according to the present invention, not only errors that can be detected by each control circuit in the telephone main body or handset, but also errors that cannot be detected by themselves, can be forcibly detected by the other control circuit. Since the initial set is performed before the start, there are many advantages such as more stable operation of the system as a whole.

[Brief explanation of the drawing]

FIG. 1 is a configuration example diagram of a control system to which the present invention is applied;
FIG. 2 is a block diagram showing an embodiment of the present invention, and FIGS. 3 and 4 are flowcharts showing an example of the operation of the present invention. 100...Radio unit, 101...Antenna, 1
02...Sending signal line, 103...Receiving signal line, 1
04...Digital signal line, 105...Power line, 2
00...Telephone body, 201...Control circuit (first), 202...Signal transmission circuit (first), 203...
...Transmission completion detection circuit, 204...Signal reception circuit (second), 205...Reception completion detection circuit, 206...
...Timer, 207...And gate, 208...
...or gate, 209...error counter, 2
DESCRIPTION OF SYMBOLS 11... Power supply control circuit, 220a... Input signal line, 220b... Select line, 221a... Segment control line, 221b... Digit control line, 300...
...Handset, 301...Control circuit (second),
302...Signal receiving circuit (second), 303...Reception completion detection circuit, 304...Signal transmission circuit (second), 305...Transmission completion detection circuit, 306...
Input means, 307...display device, 308...power supply circuit, 309...telephone receiver, 310...telephone receiver.

Claims (1)

[Claims] 1. A first control circuit, a first signal sending circuit and a first signal receiving circuit whose inputs and outputs are respectively connected to the first control circuit, and the first control circuit. a timer circuit and a counting circuit controlled by a second
a second signal sending circuit whose input and output are respectively connected to the second control circuit;
interconnection between the signal receiving circuit, the output of the first signal sending circuit and the input of the second signal receiving circuit, and the input of the first signal receiving circuit and the output of the second signal sending circuit. and a cable that transmits a signal from the first control circuit to the second control circuit via the first signal sending circuit, the cable, and the second signal receiving circuit. A timer circuit is activated by the first control circuit, and the signal from the second control circuit cannot be received by the first signal receiving circuit or the received signal does not match within a certain period of time set by the timer circuit. When an error is detected, the clock pulses are counted by the counting circuit, and when the count value of the counting circuit exceeds a predetermined value, the first control circuit controls the clock pulses of the second control circuit. A reset method configured to reset the power supply to an initial state. 2. The count value of the counting circuit is reset when the first signal receiving circuit normally receives the signal from the second control circuit within the certain period of time. Reset method described in Section 1. 3. The reset method according to claim 1, wherein the count value of the counting circuit is reset at predetermined intervals.