JPH08321891A - Automatic incoming call equipment - Google Patents

Abstract

PURPOSE: To provide an automatic incoming call equipment capable of saving power consumption and surely discriminating a noise and a call signal from each other. CONSTITUTION: The equipment is provided with a host computer 1, a modem 2 and a power supply managing equipment 3. A calling signal detection circuit 7 in the modem 2 outputs an incoming call detection signal at the time of receiving a calling signal from a telephone line 28. The power supply managing equipment 3 starts supplying power to the host computer 1 and the modem 2 from a power supply 25 at the time of receiving the incoming call detection signal. The power supply managing equipment 3 consumes less power than the host computer 1. Consequently, if the power supply managing equipment 3 is constantly worked, the presence/absence of the calling signal from the telephone line is monitored without constantly working the host computer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a modem for transmitting and receiving data to and from a telephone line, and automatically supplies electric power from a power source when an incoming call signal from the telephone line is detected. Regarding the receiving device.

[0002]

2. Description of the Related Art Conventionally, as an automatic receiving device of this kind,
There is one shown in FIG. 7 described in JP-A-61-257049. In this automatic call receiving device, the call signal detection circuit 72 of the modem 71 detects that a call signal has arrived from the telephone line 73. The incoming of the calling signal is performed by using the current of the calling signal.

The ringing signal detection circuit 72, which has detected the ringing signal, outputs to the host computer 75 an incoming call detection signal indicating that the incoming of the ringing signal has been detected. Then, the host computer 75 responds to the incoming call detection signal by
The intermittent controllable power supply 76 of the modem 71 is remotely controlled to control the supply and interruption of the power supply from the power supply 76 to the circuit in the modem 71.

Thus, the modem 7 of this automatic call receiving device
No. 1 enables stand-by reception by monitoring whether a ringing signal has arrived. Further, according to this automatic call receiving device, it is possible to wait for reception from the telephone line by using a battery-powered portable computer.

In the conventional automatic call receiving device, the power supply 75A of the host computer 75 must be in a power supply state in order to control the intermittent controllable power supply 76. Thus, keeping the power supply 75A of the host computer 75 in the power supply state only to monitor the arrival of the ringing signal is a serious waste of power when the power supply 75A is a battery.

Therefore, the host computer 75 may have a low power consumption mode called a sleep mode in addition to the power cutoff mode. The power cutoff mode is a mode in which the host computer 75 controls the peripheral device in a power cutoff state in which power is not supplied to the modem 71. On the other hand, the sleep mode means that the modem 71
Is a mode in which the host computer 75 controls the modem 71 so that the minimum power supply current flows to the modem 71 so that the host computer can only monitor signals including the ringing signal. In the sleep mode, when the call signal detection circuit 72 of the modem 71 detects a call signal from the telephone line 73, the call signal detection circuit 72 immediately outputs an incoming call detection signal to the host computer 75. Then, the host computer 75 immediately and automatically returns from the sleep mode to the normal operating state and puts the intermittent controllable power supply 76 of the modem 71 into the normal power supply state. Then, the modem 71 can respond to the call signal.

[0007]

However, since the ringing signal detection circuit 72 cannot distinguish noise such as pulse dialing sent from the telephones connected in parallel from the ringing signal, the host computer 75 cannot detect the ringing signal. There is a problem that noise may mistakenly return from the sleep mode to the normal operating state.

Furthermore, when telephones are connected in parallel to the telephone line, noise such as pulse dialing frequently occurs, so that the host computer 75 frequently returns from the sleep mode and maintains the sleep mode. There is a problem in that it is impossible to do so and a significant waste of battery power is generated.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic call receiving device capable of saving power consumption even when the host computer does not have a sleep mode. Another object of the present invention is to provide an automatic call receiving device capable of discriminating between a ringing signal and noise, preventing frequent return from sleep mode due to noise, and preventing power consumption.

[0010]

To achieve the above object, the invention of claim 1 provides a host computer for transmitting and receiving data to and from a telephone line, and digital data output from the host computer for the telephone line. To a signal suitable for transmission to the host computer, a demodulation circuit for demodulating digital data received from the telephone line into a signal suitable for input to the host computer, and a telephone call signal from the telephone line. When receiving, the current which the incoming call signal has is used to output an incoming call detection signal indicating that the incoming call signal has been received to the host computer to notify the host computer of the incoming call signal. A modem including a ringing signal detection circuit; and an operation of cutting off power from a power source to the host computer and the modem. A power management device capable of starting the supply of power from the power supply to the host computer and the modem when receiving an incoming call detection signal from the ringing signal detection circuit, and consuming less power than the host computer; It is characterized by having.

According to a second aspect of the present invention, in the automatic incoming call device according to the first aspect, when the power management device receives a signal from the ringing signal detection circuit during the power cutoff operation, the signal is output. It is characterized in that it is provided with signal discrimination means for discriminating whether or not it is an incoming call detection signal indicating an incoming call of a telephone call.

According to a third aspect of the present invention, in the automatic call receiving device according to the second aspect, the signal determining means of the power management device determines that the signal from the ringing signal detecting circuit is the incoming call detecting signal. At the time, an operation for starting the supply of electric power from the power source to the host computer and the modem is performed.

[0013]

According to the invention of claim 1, when the ringing signal detection circuit of the modem receives a telephone ringing signal from the telephone line, the current ringing signal is used to make the ringing. An incoming call detection signal indicating that a signal has arrived is output to the host computer to notify the host computer of the incoming call signal.

Then, the power management device starts the supply of power from the power supply to the host computer and the modem when receiving the incoming call detection signal from the ringing signal detection circuit. This power management device consumes less power than the host computer.

Therefore, according to the automatic call receiving device of the present invention, if the power management device is always operated, it is possible to monitor the presence or absence of a ringing signal from the telephone line without constantly operating the host computer. . Therefore, according to the present invention, it is possible to reduce the power consumption as compared with the conventional example in which the host computer needs to be constantly operated.

Further, according to the automatic call receiving device of the invention of claim 2, when the power management device is performing a power cutoff operation for cutting off power from the power supply to the host computer and the modem, When the signal discriminating means receives the signal from the call signal detecting circuit, it discriminates whether or not the signal is an incoming call detecting signal indicating an incoming call. Therefore, if this determination result is negative, it is possible to prevent the power management apparatus from operating the host computer and the modem by mistake if the power management apparatus does not start the power supply to the host computer and the modem. It can be prevented.

Therefore, according to the second aspect of the present invention, it is possible to prevent the host computer and the modem from malfunctioning due to noise from the telephone line, so that it is possible to eliminate unnecessary power consumption and save power. be able to.

According to another aspect of the present invention, in the automatic power receiving device, when the signal discriminating means discriminates that the signal from the ringing signal detecting circuit is the incoming signal, the power management device outputs the signal from the power source. The operation of starting the power supply to the host computer and the modem is performed. Therefore, according to the third aspect of the present invention, it is possible to reliably detect the arrival of the ringing signal from the telephone line and start the power supply to the host computer and the modem. Therefore, claim 3
According to the invention, the host computer and the modem do not malfunction due to noise from the telephone line, useless power consumption can be eliminated, and power can be saved.

An important point of the present invention is that the power management device has a lower function and a lower processing capability than the host computer, but the power management device monitors the incoming call signal while the power to the host computer is cut off. The power consumed by the entire automatic call receiving device when performing a call is about one hundredth of the power consumed when the host computer performs the same incoming call monitoring function.
That is the point.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments.

FIG. 1 is a block diagram of an embodiment of the automatic call receiving device of the present invention. As shown in FIG. 1, this embodiment
Host computer 1 and modem 2 as information processing devices
And a power management device 3. The modem 2 includes a modem chip 5, a telephone line interface 6 and a call signal detection circuit 7. The modem chip 5 includes a control circuit 18, a modulation circuit 20, a demodulation circuit 21, a transmission filter 22 and a reception filter 23.

The power management device 3 includes an input / output port 8, an external interrupt circuit 10, a CPU 11 and a timer function unit 1.
2, RAM 13, oscillating circuit 14, and ROM 15. The host computer 1 is connected to the control circuit 18 of the modem chip 5. The host computer 1 controls the modem 2 by exchanging signals with the control circuit 18. Also, the host computer 1
Are connected to the input / output port 8 of the power management device 3. The host computer 1 is controlled by the power management device 3 regarding power supply.

The power management device 3 is connected to the power supply 25 and controls power supply and power cutoff to the host computer 1 and the modem 2. The power management device 3 is a general-purpose one-chip microcontroller. The ROM 15 of the power management device 3 stores a control program for the above power supply and interruption. The RAM 13 also stores data used in the above program. Further, the timer function unit 12 measures time. The input / output port 8 is also responsible for connection with external devices. And CP
U11 performs signal processing from the input / output port 8,
And the above program is executed.

The power management device 3 composed of the one-chip microcontroller has a lower function than the host computer 1. Further, the CPU 11 of the power management device 3 is inferior in processing capability to the host computer 1. On the other hand, the power management device 3 is
By adopting CMOS in the process and setting the clock frequency lower than that of the host computer 1, it is possible to operate with low power consumption which is several hundredth of that of the host computer 1.

Further, the power management device 3 has a sleep mode. In this sleep mode, the oscillation circuit 1
4 stops the operation of the CPU 11 by stopping the output of the clock signal generated by the oscillation, and the external interrupt circuit 10 uses the minimum current for the falling edge of the external interrupt signal. Is a low power consumption state in which the operation of the CPU 11 can be restarted.

On the other hand, the telephone line interface 6 of the modem 2 is connected to the telephone line 28. The telephone line interface 6 electrically separates the modem chip 5 on the secondary side and the telephone line 28 on the primary side by a photo coupler and a matching transformer. Modem chip 5
Are interconnected with the host computer 1. The modem chip 5 is a one-chip microcontroller. The control circuit 18 of the modem chip 5 controls the entire modem 2. The modulation circuit 20 also modulates the digital signal from the control circuit 18 into an analog signal. Further, the transmission filter 22 has a main role of removing unnecessary signals from the signals transmitted to the telephone line 28. In addition, the demodulation circuit 2
1 demodulates an analog signal into a digital signal. Further, the reception filter 23 has a main role of shaping an analog signal input from the telephone line 28.

An analog data signal input to the modem 2 from the telephone line 28 is input to the modem chip 5 via the telephone line interface 6. The analog data signal is shaped into an analog signal by the reception filter 23 and then demodulated into a digital data signal by the demodulation circuit 21. Then, this digital data signal is output to the host computer 1 via the control circuit 18.

On the other hand, from the host computer 1 to the modem 2
First, the digital data signal input to the modem chip 5 is input to the modem chip 5. This digital data signal is input to the modulation circuit 20 via the control circuit 18, and is modulated here from the digital data signal to an analog data signal.
The analog signal is sent to the telephone line 28 via the telephone line interface 6 after the unnecessary signal component is removed by the transmission filter 22 and analog signal processing suitable for transmission on the telephone line 28 is performed. To be done.

The call signal detection circuit 7 is connected to the telephone line interface 6 and is a circuit for monitoring the arrival of a call signal from the telephone line 28. The ringing signal detection circuit 7 transmits a signal indicating the arrival of the ringing signal immediately after detecting the ringing signal. The signal indicating the incoming call is identified by the control circuit 18 in the modem chip 5 as a calling signal from the telephone line 28. The signal indicating the incoming call is also input to the CPU 11 via the input / output port 8 in the power management device 3 and is identified by the CPU 11 as a calling signal from the telephone line 28.

FIG. 2 shows the circuit configuration of the telephone line interface 6 provided in the modem 2 and the calling signal detection circuit 7.
1 shows a circuit configuration. Telephone line interface 6 above
Is a connector 30, a varistor 32, and a noise filter 33.
It has a diode bridge circuit DB, a line switching circuit 35 and a matching transformer 31. Further, the ringing signal detection circuit 7 includes a DC coupling capacitor 36,
It has a resistor 37, a photocoupler 38, a Schottky diode circuit 40, and a resistor 41. The photocoupler 38 is composed of a photodiode 38a and a phototransistor 38b, and the signal that mediates between the photodiode 38a and the phototransistor 38b is light. Therefore, the photodiode 38a and the phototransistor 38b are electrically insulated.

Telephone line interface 6 and telephone line 2
8 is directly connected by a connector 30. On the other hand, the telephone line interface 6 and the modem chip 5 are electrically insulated by using the matching transformer 31.
Therefore, the interface 6 and the modem chip 5 are interconnected so that only the AC signals are transmitted.

In this embodiment, a two-line system is used as the telephone line 28, assuming a public telephone line network or a similar private network. The varistor 32 plays a role of protecting the telephone line interface 6 and the ringing signal detection circuit 7 from the abnormal voltage superimposed on the telephone line 28. The noise filter 33 has two capacitors and two coils, and the capacitors and the coils are connected alternately. The signal from the telephone line 28 is input to the ringing signal detection circuit 7 via the connector 30, the varistor 32, and the noise filter 33 of the interface 6.

The signal input to the calling signal detection circuit 7 is
Only the AC signal component is extracted by the DC coupling capacitor 36 and input to the photodiode 38a of the photocoupler 38 via the resistor 37. This input signal is a half-wave rectified component of an AC signal determined by the polarity of the cathode of the photodiode 38a. Photo coupler 3
In accordance with the input signal current to the photo transistor 38,
The emitter-collector of b is turned on / off.

The emitter terminal of the phototransistor 38b is connected to the ground potential, and the collector terminal is connected to the Schottky diodes 40a and 40b.
The Schottky diodes 40a and 40b form the Schottky diode circuit 40. The Schottky diode 40a is the control circuit 18 in the modem chip 5.
While being connected to the Schottky diode 40b
Is connected to the input / output port 8 of the power management device 3.
Therefore, the signal from the diode 40a is input to the control circuit 18 as a detection signal, and the signal from the diode 40b is input to the input / output port 8. Since the diodes 40a and 40b are connected to the power source by the resistors 41 and 42, the signal from the diode 40a and the diode 4
The signal from 0b is pulled up to the power supply potential of the circuit to which each signal is connected.

Schottky diodes 40a and 40b
Plays a role of limiting the direction of the current due to the signal potential being pulled up so that no current flows between the signal line 43 to the control circuit 18 and the signal line 44 to the power management device 3. There is.

The pull-up voltage of the signal transmitted through the signal line 43 to the control circuit 18 in the modem chip 5 is the power supply voltage of the modem 2 and is usually at the ground potential. Also,
The pull-up potential of the signal transmitted through the signal line 44 to the input / output port 8 of the power management device 3 is in a state where the power is always on. In this case, if the current direction is not limited by the Schottky diode circuit 40,
The current flows from the signal line 44 to the signal line 43.

The call signal detection circuit 7 uses the signal output from the phototransistor 38b as an open collector output. Therefore, when no call signal is input to the call signal detection circuit 7 from the telephone line 28, the resistor 41
And 42 can prevent the signal pulled up to the power supply potential from flowing an unnecessary current to the detection circuit 7. Therefore, power consumption can be reduced.

FIG. 3 shows the ringing signal input to the telephone line interface 6 of the modem 2 from the telephone line 28 and the waveform of the signal at each position in the ringing signal detection circuit 7. The operation of the call signal detection circuit 7 will be described with reference to FIGS. 3 and 2.

First, as shown in FIG. 3A, the telephone line 2 is connected through the connector 30 of the telephone line interface 6.
The call signal W1 input from 8 is not an abnormal voltage. Then, the calling signal W1 is directly input to the calling signal detection circuit 7 if it does not include unnecessary noise outside the calling signal standard. FIG. 3B shows a partially enlarged waveform W2 of the calling signal W1.

Next, as shown in FIG. 3C, the calling signal W1 is half-wave rectified by the diode D1 and becomes an input signal W3 to the photodiode 38a of the photocoupler 38. This input signal W3 is applied to the photodiode 3
Phototransistor 38b converted to light by 8a
It becomes the base terminal input signal of. Phototransistor 38
b turns on / off between the emitter terminal and the collector terminal in an analog manner according to the strength / weakness of the base terminal input signal consisting of the light.

The phototransistor 38b has an emitter terminal grounded to the ground potential, and has an open collector output. In addition, the phototransistor 38
The collector terminal of b is pulled up to the power supply potential by resistors 41 and 42. Therefore, as shown in FIG. 3D, the phototransistor 38b outputs the output signal W4 obtained by inverting the base terminal input signal.

By the way, when the input signal voltage to the photodiode 38a is below a specified value, the phototransistor 38b does not operate and does not output a signal. The ringing signal detection circuit 7 adjusts the specified value of the input signal voltage to a voltage according to the telephone line standard.

The control circuit 18 of the modem chip 5 and the input / output port 8 of the power management device 3 are connected to the phototransistor 38b.
The analog output signal W4 output by the above is digitally waveform-shaped so that the host computer 1 and the CPU 11 of the power management device 3 can easily process the signal, and the ring signal W5 shown in FIG. The ring signal W5 whose waveform has been digitally shaped is taken in by the CPU 11 of the host computer 1 and the power management device 3 as a digital signal.

Next, the signal processing after the ring signal W5 is input to the host computer 1 and the power management device 3 will be described with reference to FIGS. When power is supplied to the host computer 1 and the modem 2, the ring signal W5 is immediately transmitted to the host computer 1. Then, the host computer 1 closes the line switching circuit 35 of the telephone line interface 6 of the modem 2 to make the modem 2 ready to receive data, and the analog data from the telephone line 28 is demodulated via the modem 2. Receive as digital data.

On the other hand, when the power supply to the host computer 1 and the modem 2 is cut off, the power management device 3 outputs the output signal from the call signal detection circuit 7 of the modem 2 to the CPU 11 via the input / output port 8. receive. by this,
The CPU 11 starts power supply to the host computer 1 and the modem 2. By the way, before starting this power, RO
The program included in M15 determines whether the output signal from the detection circuit 7 is a ring signal or noise such as pulse dialing transmitted from a telephone connected in parallel.

Even when the power management device 3 is in the sleep mode, the external interrupt circuit 10 detects the falling edge of the output signal from the detection circuit 7 so that the oscillation circuit 14 oscillates the clock. Start. After a certain period of clock stabilization period has elapsed since the start of this oscillation,
The CPU 11 starts operation and causes the power supply 25 to start supplying power to the host computer 1 and the modem 2. Then, the host computer 1 closes the line switching circuit 35 of the telephone line interface 6 shown in FIG.
The analog data from 8 is received via the modem 2 as demodulated digital data.

Next, the power management unit 3 determines whether the output signal from the ringing signal detection circuit 7 is a ring signal or noise such as pulse dialing transmitted from a telephone connected in parallel. And the procedure is explained.

An enlarged waveform of the ring signal W5 having the waveform shown in FIG. 3 (E) is shown in FIG. 3 (F). As shown in FIG. 3 (F), the cycle RT of the calling signal is defined in the range from 15 milliseconds to 65 milliseconds as a standard of the telephone line. The minimum value RLmin and the maximum value R of the low level period RL in one cycle
Lmax, and the minimum value RHmin and the maximum value RHmax of the high level period RH in one cycle vary depending on the electrical characteristics of the ringing signal detection circuit 7. Further, since the maximum number of dial pulses from the telephones connected in parallel is 10, the calling signal detection circuit 7 determines that the dial pulse is not generated when the number of pulses exceeds 10. Therefore, the power management device 3 determines that the signal from the telephone line 28 is a ring signal only when all of the following conditions are satisfied.

Minimum value RLmin <Low level period RL <Maximum value RLmax Minimum value RHmin <High level period RH <Maximum value RHmax 15 ms <Ring signal period RT <65 ms (where RT = RL + RH) Number of dial pulses 11 or more, the CPU 11 of the power management device 3 uses the program stored in the ROM 15 so that the output signal from the calling signal detection circuit 7 is a ring signal or a pulse sent from a telephone connected in parallel. Whether it is noise due to dialing or the like is discriminated by referring to the above conditions. This determination method will be described below with reference to the flowcharts shown in FIGS. 4 and 5.

First, in step S1, the output signal from the call signal detection circuit 7 is sent to the CPU 1 via the input / output port 8.
1 detects. Next, in step S2, a timer is initialized to measure the low level period of the output signal, and then time counting is started. Next, in step S3, it is determined whether or not the output signal is at the low level. If the output signal is at the low level, the process proceeds to step S4. If not, the process proceeds to step S5. In step S4, it is determined whether or not the time measured by the timer is less than or equal to the maximum value of the low level. If it is less than or equal to the maximum value, the process returns to step S3, and if it exceeds the maximum value, the process proceeds to step S24. In step S24, it is determined that the output signal is noise.

Next, in step S5, the timer is initialized to measure the high level period, and then time counting is started. Next, in step S6, it is determined whether or not the output signal is at a high level. When it is determined that the output signal is at a high level, the process proceeds to step S7. When it is determined that the output signal is not at the high level, the process proceeds to step S8. In step S7, it is determined whether or not the timer value is less than or equal to the maximum value RHmax, and if it is determined that the timer value is less than or equal to RHmax, step S6.
If it is determined that the measured value is not less than RHmax, the process proceeds to step S24, and it is determined that the output signal is noise.

When it is determined in step S6 that the output signal is not at the high level, it is the end of the high level period of the output signal. Therefore, steps S2 to S
By the processes up to 7, it is possible to reliably prevent the timer from starting the time measurement in the middle of the low level period or the high level period of the output signal. Therefore, the low level period and the high level period of the output signal can be reliably detected by the process from the next step S8.

In step S8, a counter for counting the number of pulses of the output signal is initialized. Next, step S9
Then, the timer is initialized to measure the low level period of the output signal, and then time counting is started. Next, in step S10, it is determined whether or not the output signal is at the low level. If it is determined that the output signal is at the low level, the process proceeds to step S11. If it is determined that the output signal is not at the low level, the process proceeds to step S12. In step S11, it is determined whether or not the measured value of the timer is less than or equal to the maximum value RLmax, and if it is determined that it is less than or equal to RLmax, the process returns to step S10, and
If it is determined that it is not less than or equal to x, the process proceeds to step S24.
In step S24, it is determined that the output signal is noise.

In step S12, it is determined whether or not the timed value of the timer is the minimum value RLmin of the low level or more. When it is determined that it is the minimum value RLmin or more, the process proceeds to step S13 and it is determined that it is not more than the minimum value RLmin. Sometimes the process proceeds to step S24. In step S24, it is determined that the output signal is noise.

In step S13, the clocking of the timer is stopped, and the clocked value at this time is stored as the low level period RL of the output signal.

Next, in step S14, the timer is initialized. Next, in step S15, it is determined whether or not the output signal is at the high level. When it is determined that the output signal is at the high level, the process proceeds to step S16. When it is determined that the output signal is not at the high level, the process proceeds to step S17. . In step S16, it is determined whether or not the measured value of the timer is less than or equal to the maximum value RHmax. When it is determined that it is less than or equal to the maximum value RHmax, the process returns to step S15, and when it is determined that it is not less than or equal to the maximum value RHmax, the process proceeds to step S24. . Step S2
At 4, it is determined that the output signal is noise.

In step S17, it is determined whether or not the timer value is equal to or greater than the minimum value RHmin, and the minimum value RHmin is determined.
When it is determined that it is the above or more, the process proceeds to step S18, and when it is determined that it is not the minimum value RHmin or more, the process is step S2.
Go to 4. In step S24, it is determined that the output signal is noise.

In step S18, the counting of the timer is stopped, and the measured value of the timer at this time is stored as the high level period RH of the output signal.

Next, in step S19, it is determined whether the sum (RH + RL) of the low level period RL and the high level period RH of the output signal measured by the timer is 15 milliseconds or longer. If it is determined that there is a step S
If it is determined that the time is not longer than 15 milliseconds in step 20, the process proceeds to step S24 and it is determined that the output signal is noise.

In step S20, the above sum (RH + RL)
Is less than or equal to 65 milliseconds, and if it is less than or equal to 65 milliseconds, the process proceeds to step S21 and 65
If it is determined that it is not less than millisecond, the process proceeds to step S24 and it is determined that the output signal is noise.

In step S21, the count value of the counter initialized in step S8 is incremented by one. Next, in step S22, it is determined whether or not the count value of the counter is 11 or more. When it is determined that the count value of the counter is 11 or more, the process proceeds to step S23, and the count value of the counter is not 11 or more. When it is determined, the process returns to step S9.

Next, the operation of the embodiment having the above configuration will be described with reference to the timing chart shown in FIG.

As shown by the low level solid line in FIG. 6 (D), the power to the host 1 and the modem 2 is cut off, and the power management device 3 goes to sleep as shown by the low level solid line in FIG. 6 (C). In the mode, the entire apparatus of this embodiment is in the minimum power consumption state. In this minimum power state, the CPU 11 of the power management device 3 causes the telephone line 28
The operation from the detection of the ringing signal of the above to the reception of the data from the telephone line 28 by the host 1 through the modem 2 will be described below.

First, from the telephone line 28 to the modem 2, as shown in FIG.
When the call signal Sc shown in (A) arrives, the call signal Sc is sent to the call signal detection circuit 7 via the telephone line interface 6.

The call signal detection circuit 7 uses the voltage possessed by the call signal Sc from the telephone line 28 to call the call signal S.
c is converted into a digital output signal, that is, a ring signal shown in FIG. 6B, which can be appropriately signal-processed by the host 1 or the power management device 3. Then, the calling signal detection circuit 7 sends the ring signal to the power management device 3.

The ring signal is sent to the external interrupt circuit 10 via the input / output port 8 of the power management device 3. When the external interrupt circuit 10 detects the falling edge of the ring signal, the oscillator circuit 14 of the power management device 3 starts clock oscillation. Then, as shown in FIG. 6C, the CPU 11 of the power management apparatus 3 starts operating after the lapse of a predetermined clock stabilization period. Then, as shown in FIG.
As shown in (D), the CPU 11 causes the power supply 25 to start supplying power to the host 1 and the modem 2.

The host 1 to which the power is supplied closes the line switching circuit 35 of the telephone line interface 6 of the modem 2 so that the modem 2 can receive data. The modem 2 receives the analog data signal input from the telephone line 28 at the telephone line interface 6. The analog data signal from the telephone line 28 is analog signal shaped by the reception filter 23 of the modem chip 5, demodulated into a digital data signal by the demodulation circuit 21, and further output to the host 1 via the control circuit 18. It

Then, the host 1 activates a program capable of transmitting and receiving data, receives data from the modem 2 and processes the signal.

Next, when the entire apparatus of this embodiment is in the above-mentioned minimum power consumption state, the CPU 1 of the power management apparatus 3
1 receives a signal from the telephone line 28 and determines whether the received signal is a ringing signal or noise such as pulse dialing transmitted from a telephone connected in parallel, and after this determination The operation until the host 1 receives the data from the telephone line 28 via the modem 2 will be described.

First, when a signal from the telephone line 28 is received by the modem 2, the received signal is sent to the call signal detection circuit 7 via the telephone line interface 6.

The ringing signal detection circuit 7 uses the voltage possessed by the signal from the telephone line 28 to output the output signal which allows the host 1 or the power management device 3 to perform predetermined signal processing (see FIG. (See B)). Then, the calling signal detection circuit 7 sends the output signal to the power management device 3. If the voltage of the signal from the telephone line 28 does not reach the detection voltage of the ringing signal detection circuit 7, this signal is not converted into an output signal and is not sent to the power management device 3.

The call signal detection circuit 7 sends the output signal to the external interrupt circuit 10 via the input / output port 8 of the power management device 3. As shown in FIG. 6C, the external interrupt circuit 1
When 0 detects the falling edge of the output signal, the oscillation circuit 14 starts clock oscillation. The CPU 11 of the power management device 3 starts operating after a predetermined clock stabilization period has elapsed since the start of this oscillation.

The CPU 11 executes the program stored in the ROM 15 to determine whether the output signal is a ring signal or noise.

If the CPU 11 executing this program determines that the output signal is a ring signal, the CPU 11
Controls the power management device 3 so as to immediately supply power to the host 1 and the modem 2. The host 1 to which this power is supplied closes the line switching circuit 35 of the modem 2 so that the modem 2 can receive data. The modem 2 receives the analog data signal input from the telephone line 28 at the telephone line interface 6. The analog data signal is shaped into an analog signal by the reception filter 23 of the modem chip 2 and then demodulated into a digital data signal by the demodulation circuit 21. This digital data signal is output to the host 1 via the control circuit 18. Then, the host 1 activates a program capable of transmitting and receiving data, receives data from the modem 2 and processes the signal.

On the other hand, by executing the program stored in the ROM 15 of the power management device 3, the C
When the PU 11 determines that the output signal is noise,
The CPU 11 controls the power management device 3 so as to cut off power to the host 1 and the modem 2. And C
PU11 stops operation | movement and the power management device 3 becomes sleep mode again.

Therefore, according to the automatic call receiving device of this embodiment, if the power management device 3 is always operated, the presence or absence of a ringing signal from the telephone line 28 can be monitored even if the host computer 1 is not always operated. can do. Therefore, according to this embodiment, the power consumption can be reduced as compared with the conventional example in which the host computer 1 needs to be constantly operated.

Further, according to this embodiment, the CPU 11 of the power supply management device 3 operates while the power supply management device 3 is executing the power cutoff operation for cutting off the power supply from the power supply 25 to the host computer 1 and the modem 2. , The calling signal detection circuit 7
When the signal is received from, it is determined whether this signal is an incoming call detection signal indicating an incoming call. When the result of this determination is negative, the power management device 3 prevents the power supply from the power supply 25 to the host computer 1 and the modem 2. Therefore, it is possible to avoid frequent malfunctions of the computer 1 and the modem 2 due to noise such as dialing noise. Therefore, useless power consumption can be eliminated and power can be saved.

When it is determined that the signal from the ringing signal detection circuit 7 is the incoming call detection signal, the power source 2
The operation for starting the power supply from 5 to the host computer 1 and the modem 2 is performed. Therefore, according to this embodiment, it is possible to reliably detect the arrival of the ringing signal from the telephone line 28 and start the power supply to the host computer 1 and the modem 2. Therefore, the telephone line 28
Noise from the host computer 1 and modem 2
It is possible to avoid wasteful power consumption and save power consumption.

[0079]

As is apparent from the above description, in the automatic call receiving device according to the first aspect of the invention, when the call signal detection circuit of the modem receives the call signal from the telephone line, the call is received. Using the current that the ringing signal has,
An incoming call detection signal indicating that the call signal has arrived is output to the host computer to notify the host computer of the incoming call signal.

Then, the power management apparatus starts the supply of power from the power source to the host computer and the modem when receiving the incoming call detection signal from the ringing signal detection circuit. This power management device consumes less power than the host computer.

Therefore, according to the automatic call receiving device of the present invention, if the power management device is always operated, it is possible to monitor the presence or absence of the ringing signal from the telephone line without constantly operating the host computer. . Therefore, according to the present invention, it is possible to reduce the power consumption as compared with the conventional example in which the host computer needs to be constantly operated. Therefore, according to the present invention, it is possible to realize battery driving and to make it portable.

According to the second aspect of the present invention, when the power management device is performing a power cutoff operation for cutting off power from the power supply to the host computer and the modem, When the signal discriminating means receives the signal from the call signal detecting circuit, it discriminates whether or not the signal is an incoming call detecting signal indicating an incoming call. Therefore, if this determination result is negative, it is possible to prevent the power management apparatus from operating the host computer and the modem by mistake if the power management apparatus does not start the power supply to the host computer and the modem. It can be prevented.

Therefore, according to the second aspect of the present invention, it is possible to prevent the host computer and the modem from malfunctioning due to noise from the telephone line, so that it is possible to eliminate unnecessary power consumption and save power. be able to.

According to another aspect of the automatic call-receiving device of the present invention, the power-supply management device outputs the signal from the power supply when the signal determining means determines that the signal from the ringing signal detection circuit is the incoming signal. The operation of starting the power supply to the host computer and the modem is performed. Therefore, according to the third aspect of the present invention, it is possible to reliably detect the arrival of the ringing signal from the telephone line and start the power supply to the host computer and the modem. Therefore, claim 3
According to the invention, the host computer and the modem do not malfunction due to noise from the telephone line, useless power consumption can be eliminated, and power can be saved. Therefore, in addition to being battery-powered and portable, it is possible to wait for reception of data with a minimum amount of power, even from a telephone line that generates a lot of noise.

The point of the present invention is that the power supply management device has a lower function and a lower processing capacity than the host computer, but the power supply management device monitors the incoming call signal while the power supply to the host computer is cut off. The power consumed by the entire automatic call receiving device is about one hundredth of the power consumed when the host computer performs the same call monitoring function.
Is enough.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an automatic call receiving device of the present invention and showing connections between a modem, a host, a power management device and a telephone line.

FIG. 2 is a circuit diagram showing a telephone line interface and a call signal detection circuit provided in the modem of the above embodiment.

FIG. 3 is a waveform chart showing waveforms of a ringing signal and a ring signal in the above embodiment.

FIG. 4 is a diagram showing a first half of a flow chart showing a procedure for discriminating between a ring signal and noise in the embodiment.

FIG. 5 is a diagram showing the latter half of the flowchart.

FIG. 6 is a timing chart showing transitions from detection of a signal from a telephone line to power supply to a host and a modem separately in the case of a ringing signal and the case of noise in the above embodiment.

FIG. 7 is a block diagram of a conventional automatic call receiving device.

[Explanation of symbols]

1 ... Host computer, 2 ... Modem, 3 ... Power management device, 5 ... Modem chip, 6 ... Telephone line interface, 7 ... Call signal detection circuit, 8 ... I / O port, 10 ...
External interrupt circuit, 11 ... CPU, 12 ... Timer function unit, 1
3 ... RAM, 14 ... Starting circuit, 15 ... ROM, 30 ... Connector, 31 ... Matching transformer, 32 ... Varistor,
33 ... Noise filter, 35 ... Line switching circuit, DB ... Diode bridge circuit, 36 ... DC coupling capacitor, 38 ... Photocoupler, 38a ... Photodiode, 38b ... Phototransistor, 40 ... Schottky diode circuit.

Claims (3)

[Claims] 1. A host computer for transmitting and receiving data to and from a telephone line, a modulation circuit for modulating digital data output from the host computer into a signal suitable for transmitting to the telephone line, and receiving from the telephone line. A demodulation circuit that demodulates the digital data into a signal suitable for input to the host computer, and when the telephone call signal from the telephone line is received, the current that the incoming call signal has is used. A modem including a ringing signal detection circuit that outputs an incoming call detection signal indicating that the ringing signal has arrived to the host computer to notify the host computer of the arrival of the ringing signal, and the host computer and the modem from a power source. To shut off the power to the power supply and the power supply when the incoming call detection signal from the ringing signal detection circuit is received. Luo operation and for starting the supply of power to the host computer and the modem are possible, automatic call device characterized by comprising a low power consumption power management device than the host computer. 2. The automatic call receiving device according to claim 1, wherein when the power management device receives a signal from the ringing signal detection circuit during the power cutoff operation, this signal indicates an incoming call of a telephone call. An automatic call receiving device comprising a signal determining means for determining whether or not the signal is an incoming call detection signal. 3. The automatic call-receiving device according to claim 2, wherein the power management device outputs the signal from the power supply when the signal determining means determines that the signal from the ringing signal detection circuit is an incoming-call detection signal. An automatic call receiving device characterized by performing an operation of starting supply of electric power to a host computer and a modem.