JP3199903B2 - Information communication terminal device and control method therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable information communication terminal device such as a portable telephone which requires low power consumption and a control method thereof.

[0002]

2. Description of the Related Art Advances in semiconductor technology have led to miniaturization of devices, and information communication terminal devices such as telephones, electronic organizers, word processors, and personal computers have become smaller and more portable. These information communication terminal devices often use a battery as a power source so that they can be used anytime and anywhere.
However, the battery is different from the AC power supply (AC100V).
There is a disadvantage that the use time is limited (it cannot be used for a long time). Therefore, low power consumption is a common problem for these information communication terminals.

Conventionally, as shown in, for example, JP-A-3-252285, a power supply is turned on only when the apparatus is operating,
When not in use, the power was turned off to reduce power consumption.

[0004]

In the prior art, the power consumption is reduced when the apparatus is not used. However, there is no mention of suppressing the power during operation.
Power saving when the device is actually operating has not been realized.

An object of the present invention is to realize power saving during operation of a device.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention monitors the ambient temperature with temperature measuring means, and when the ambient temperature is high, increases the power supply voltage so that high-speed operation can be realized. When the temperature is low, the power supply voltage at the time of design in consideration of the operation margin of the circuit (for example, the power supply voltage at the time of design is 4.5 V with respect to the power supply voltage of 5 V for normal operation),
The power supply voltage is reduced to achieve low power consumption.

Further, according to the present invention, a critical path is selected from a control circuit, the operation state is monitored by a critical path test circuit for testing the critical path, and when the critical path malfunctions, the power supply voltage is increased to increase the critical voltage. When the path is in a normal state, the power supply voltage is reduced.

In the present invention, a switch is provided so that the user can switch the power supply voltage of the information communication terminal device by himself / herself, and the right to determine the switching of the power supply voltage is left to the user.

Further, the present invention is provided with a display so that a user can monitor whether or not a normal operation is performed when the power supply voltage is lowered, so as to notify the user of a malfunction state.

Further, according to the present invention, a switch is provided so that two power supplies of the same output voltage can be switched and connected in series and in parallel, and in a poor environment where the ambient temperature is high, the power supplies are connected in series to provide a high-speed connection. When the ambient temperature is low, the power supply is connected in parallel so that the power supply can be used for a long time at a low voltage.

Also, the present invention measures the ambient temperature when the power switch is turned on, that is, before the information communication terminal actually operates, increases the power supply voltage when the temperature is high, and increases the power supply voltage when the temperature is low. This is to lower the voltage.

Further, according to the present invention, the ambient temperature is measured during the idle time of the processing of the CPU of the control circuit of the information communication terminal device, and the power supply voltage is raised when the temperature is high, and the power supply voltage is lowered when the temperature is low. Is what you do.

Further, according to the present invention, the ambient temperature is measured at regular time intervals, and when the temperature is high, the power supply voltage is increased, and when the temperature is low, the power supply voltage is decreased.

[0014]

According to the present invention, the power supply voltage is controlled so as to adaptively lower the operating margin of the circuit so as to be as close to zero as possible according to the operating environment such as the ambient temperature.
Low power consumption can be realized.

Further, according to the present invention, a critical path having the smallest operation margin is selected and the power supply voltage is controlled to the lowest level just before the critical path operates normally, so that low power consumption can be realized.

Further, according to the present invention, since the user can switch the power supply voltage of the information communication terminal device, low power consumption can be realized.

Further, according to the present invention, when the power supply voltage is lowered, it is possible to confirm whether or not the device is operating normally.
Malfunction can be prevented.

Further, according to the present invention, the two batteries are switched and used in series and in parallel, so that the batteries can be used efficiently.

Further, according to the present invention, when the power switch is turned on, the power supply voltage is set, so that the processing performance of the apparatus does not deteriorate.

According to the present invention, the power supply voltage is switched during the idle time of the processing of the CPU of the control circuit.
The processing capacity of the device does not decrease.

Further, according to the present invention, since the power supply voltage is switched at regular time intervals, the power supply voltage does not operate for a long time at a low voltage, and malfunction can be prevented.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A conventional portable information terminal device has been designed with an operating margin in a power supply voltage so as to operate even in a bad environment. For example, the power supply voltage is low (for example, 4.5 V)
By the way, it was designed to operate normally, and actually, it was operated at a higher voltage (for example, 5 V).

However, these devices are rarely used in a hostile environment, for example, in the desert, tropics, outdoors in summer, etc., and usually have a relatively good environment, and are effective for cooling offices, homes, automobiles and the like. It is often used in places that are not. In this case, setting the power supply voltage to 5 V is a waste of power consumption, and the power supply voltage of 4.5 V at the time of design sufficiently operates normally.
If the power supply voltage is set to 4.5 V, it is possible to reduce power consumption by about 20%.

The present invention aims at reducing power consumption by controlling the power supply voltage by utilizing such an operation margin at the time of design.

One embodiment of the present invention will be described with reference to FIG.
The portable information communication terminal of the present invention comprises a control circuit 5, a power supply 3-1 having a low output voltage, a power supply 3-2 having a high output voltage, a temperature sensor 2, a voltage control circuit 1, and a power supply voltage changeover switch 4. I have. Usually, the power supply voltage switch 4 is connected to a power supply 3-1 (4.5 V) having a low output voltage. The voltage control circuit 1 measures the temperature information 101 from the temperature sensor 2 and determines that the operating environment has deteriorated when the temperature is higher than a predetermined temperature (for example, 40 degrees).
Is switched to the power supply 3-2 (5V) having a high output voltage. As a result, the power supply voltage of the control circuit 5 increases, so that the control circuit 5 can operate at high speed and operate normally even in a poor environment.

FIG. 2 shows a voltage switching sequence.
This figure shows how the power supply voltage is switched in response to a change in the ambient temperature. The horizontal axis indicates time.
The power supply voltage switching threshold is set to 40 degrees. At first, since the ambient temperature is lower than 40 degrees, the power supply voltage is selected to be the power supply 3-1 to be 4.5V. At time t1, the ambient temperature becomes higher than 40 degrees, the power supply switches from 3-1 to 3-2, and the power supply voltage becomes 5V. Then, until time t2, 5
When the ambient temperature falls below 40 degrees at time t2, the power supply switches again from 3-2 to 3-1 and the power supply voltage becomes 4.5V.

The second embodiment of the present invention measures a critical path and switches the power supply voltage. This embodiment will be described with reference to FIG. The portable information communication terminal of the present invention includes a control circuit 5, a power supply 3-1 having a low output voltage, a power supply 3-2 having a high output voltage, a voltage control circuit 1, and a power supply voltage changeover switch 4. The control circuit 5 includes a CPU (C
central processing unit) 10, ROM 11, RAM 1
2, a dedicated hardware 13 such as an arithmetic unit. C
The PU 10 includes a ROM 11, a RAM 12, and a dedicated hardware 1.
3. Control the voltage control circuit 1.

The dedicated hardware 13 is usually composed of a plurality of arithmetic units. Among them, the one with the smallest operation margin is the critical path circuit 14. The critical path circuit 14 includes a selector 20 for switching between a normal data path and a path for checking a critical path, and a latch 2.
1, 23, and an arithmetic unit 22. The critical path is the operation unit 22 between the latch 21 and the latch 23.
And

When the critical path check signal is turned on, the selector 20 loads test data from the CPU 10 to the latch 21. After the operation, the CPU 10 reads out the operation result 201 stored in the latch 23,
The calculated value is compared with the expected value stored in the OM 11 (or the RAM 12). If the values match, the arithmetic unit 22 is determined to be operating normally. If not, the arithmetic unit 22 is determined to have malfunctioned. If a malfunction occurs, change the power supply from 3-1 to 3-2.
And the voltage is set to 5 V, and the critical path is checked again.

As described above, the device is operated while the operation of the critical path circuit 14 is confirmed, and a power supply voltage within a range that does not cause malfunction is selected, thereby realizing low power consumption.

In the present embodiment, the critical path is used as the arithmetic unit. However, when the ROM and the RAM become the critical paths, the CPU may check the read / write of the memory.

Third and fourth embodiments will be described with reference to FIG. In the third embodiment, the power supply voltage is controlled by an external switch. The portable information communication terminal of the present invention,
Control circuit 5, power supply 3-1 having a low output voltage, power supply 3-1 having a high output voltage 2-2, voltage control circuit 1, power supply voltage changeover switch 4, voltage selection switch 40, voltage selection switch interface circuit 41, display LED 50, display It comprises a circuit 51. The CPU 10 in the control circuit 5 reads the state of the voltage selection switch 40 via the voltage selection switch interface circuit 41. When in the off state, the voltage control circuit 1 is instructed to select the power supply 3-1 with a low power supply voltage, and in the on state, the voltage control circuit 1 is selected with the power supply 3-2 with a high power supply voltage. To instruct. As described above, according to the present invention, the user can switch the power supply voltage.

In the fourth embodiment, the CPU 10 monitors the critical path of the dedicated hardware 13 and displays an LED 50 via the display control circuit 51 when a malfunction occurs. As a result, the user can immediately know whether or not the device has malfunctioned, and in the event of a malfunction, it is possible to immediately increase the power supply voltage.

Next, an example of the configuration of the power supply and the power supply switch of the fifth embodiment will be described with reference to FIG. The power supply 3 and the power supply switch 4 include a battery 3-1 ', a battery 3-2', a switch 4-1 and a switch 4-2. Here, the description will be given on the assumption that the voltages of the two batteries are 2.5 V, but any voltage may be used. When the voltage control circuit 1 selects a high voltage, the switch 4-1 opens, and the switch 4-2 is connected to the positive pole of the battery 3-1 '. As a result, the two batteries are connected in series, and the voltage output voltage VCC becomes twice the voltage (5 V). When the voltage control circuit 1 selects a low voltage, the switch 4-1 is closed and the switch 4-2 is connected to the ground. As a result, the two batteries are connected in parallel, and the voltage output voltage VCC becomes 2.5 V, but operates for twice the normal time.

In the present embodiment, the power supply has been described as outputting a specific voltage such as a battery. However, a switching regulator may be used to control the power supply voltage to take a continuous value in an analog manner.

The sixth, seventh, and eighth embodiments relating to the switching timing of the power supply voltage will be described below and described.

(1) Immediately after the power-on switch of the power supply is pressed (sixth embodiment) When the power supply is turned on, the ambient temperature or the critical path is checked and the power supply is switched, so that the processing overhead of the apparatus does not occur. .

(2) The idle time of the processing of the CPU 10 (the seventh
Example) Since the ambient temperature or the critical path is checked during the idle time of the processing of the CPU 10 and the power supply is switched, the overhead of the processing of the apparatus does not occur.

(3) At Specific Time Intervals (Eighth Embodiment) At a specific time interval, the ambient temperature or the critical path is checked to switch the power supply. Therefore, even if the power supply voltage is lowered, the control circuit malfunctions. Even so, the period is short.

Which of these timings to select depends on the application of the device. Moreover, you may combine each method.

The present invention is not limited to information communication terminals, but can be applied to devices that operate on batteries, such as household electric appliances and games.

[0042]

According to the present invention, it is possible to reduce power consumption when a portable information communication terminal device is operated.
The information communication terminal device can be used for a long time with the same battery as the conventional one.

[Brief description of the drawings]

FIG. 1 is a block diagram of an information communication terminal according to an embodiment of the present invention in which ambient temperature is measured and power consumption is reduced by voltage control.

FIG. 2 is a time chart of FIG. 1;

FIG. 3 is a block diagram of a second embodiment of the present invention of an information communication terminal in which a critical path is measured and power consumption is reduced by voltage control.

FIG. 4 is a block diagram of the third and fourth embodiments of the present invention of an information communication terminal capable of controlling the voltage by an external switch and monitoring the internal state by LED display.

FIG. 5 is a diagram showing a power supply and a switching circuit thereof according to a fifth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Voltage control circuit, 2 ... Temperature sensor, 3 ... Power supply, 4 ... Power supply changeover switch, 5 ... Control circuit, 200 ... Information communication terminal.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masao Hotta 1-280 Higashi Koikebo, Kokubunji-shi, Tokyo Central Research Laboratory, Hitachi, Ltd. (56) References JP-A-64-72215 (JP, A) Akira Mikai 58-48150 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q 7/00-7/38 H04B 1/38

Claims (10)

(57) [Claims] 1. A temperature measuring means for measuring an ambient temperature, and a power supply
A power supply for outputting a voltage, and the power supply
Under pressure and for a circuit according to the measurement result of the temperature measuring means
And voltage control means for outputting a power supply voltage, the power collector for the circuit
And a circuit that operates by receiving a voltage , wherein the voltage control means increases the first voltage in the case of the first ambient temperature.
The circuit is supplied to the circuit as a power supply voltage for the circuit.
The first voltage when the first ambient temperature is higher than the ambient voltage;
The second voltage having a higher voltage than the above is set as the circuit power supply voltage.
An information communication terminal device for supplying the information communication terminal to the circuit . 2. An information communication terminal device comprising: means for testing a critical path; a power supply having a plurality of output voltages; and voltage control means for increasing a power supply voltage when the critical path malfunctions. 3. The voltage control means according to claim 1, wherein said voltage control means switches a power supply of a plurality of output voltages by a switch.
And outputting the circuit power supply voltage . 4. An information communication terminal device according to claim 1, wherein said voltage control means has a power supply connection switching means for switching said power supply in parallel or in series. 5. The information communication terminal device according to claim 1, wherein the information communication terminal device has a display for displaying a malfunction of the circuit. 6. The information communication terminal device according to claim 1, wherein an ambient temperature is measured when a power switch of the information communication terminal device is turned on. 7. The information communication terminal device according to claim 1, wherein an ambient temperature is measured during an idle time of processing. 8. The information communication terminal according to claim 1, wherein the ambient temperature is measured at regular time intervals. 9. A means for testing a critical path, a power supply for outputting a power supply voltage, and a power supply voltage for a circuit in response to the power supply voltage output from the power supply and outputting a power supply voltage for a circuit, and when the critical path malfunctions, An information communication terminal device, comprising: voltage control means for increasing and outputting a circuit power supply voltage; and a circuit which operates upon receiving the circuit power supply voltage. 10. In any one of claims 1 to 9, wherein the information communication terminal apparatus having the power supply as the battery, the information communication terminal apparatus, wherein the information communication terminal apparatus is portable.