JPH054232U - Small electronic calculator - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is equipped with a large-capacity memory, for example.
It is an object of the present invention to provide a small electronic computer that can save power even when it has high functionality. [Structure] A low-voltage (3V) driven CPU 11 is provided with a low-voltage (3V) → high-voltage (5V) booster 13, and low-voltage and high-voltage gates GL and GH are used when accessing data with an external ROM 16 or RAM 17 driven by high voltage. It is configured so that a high-voltage power supply can be selectively obtained by controlling the on / off of each.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a small electronic computer with low power consumption and high functionality.

[0002]

[Prior Art]

 Generally, small electronic calculators such as portable calculators and pocket computers use a 3V drive CPU chip with a low drive voltage in order to save power. On the other hand, some recent small electronic computers use a 5V drive CPU chip with a high drive voltage in order to achieve higher functionality and higher processing speed.

That is, if a large-capacity memory or the like is used to improve the functionality of a small-sized electronic computer, the driving voltage itself is high, for example, 5V, so it is necessary to use the 5V-driven CPU chip.

[0004]

[Problems to be solved by the device]

 However, if all of the internal drive voltage is driven to a high voltage (5 V) to improve the functionality of the pocket computer or the like, the power saving, which is the most important in a small device, is hindered.

Therefore, it is conceivable to change the high-voltage drive circuit component to the low-voltage drive, but this causes a problem in cost, and it is technically extremely difficult to drive the large-capacity memory etc. to the low-voltage drive. There is.

The present invention has been made in view of the above-mentioned problems, and provides a small electronic computer capable of achieving power saving even when high performance is achieved such as mounting a large capacity memory. The purpose is to

[0007]

[Means for Solving the Problems] That is, a small-sized electronic computer according to the present invention comprises a voltage generating means for generating a plurality of voltages, a plurality of devices driven by different voltages, and an access of the plurality of devices. And a voltage selection means for selecting the voltage generated by the voltage generation means according to the device.

[0008]

[Action]

 That is, for example, by providing a low-voltage → high-voltage booster circuit inside a low-voltage driven CPU so that a high-voltage power source can be selectively obtained when accessing data with a high-voltage driven large-capacity memory, the high-voltage driving period can be minimized. Will be suppressed to.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a small electronic computer. In FIG. 1, reference numeral 11 denotes a CPU. Inside the CPU 11, a power source for a control unit 12 and 3V that performs a control operation according to a preset program. In addition to the booster 13 that boosts the voltage to 5V, the buffer 14 that relays the access signal and the access data with the attached device, an internal ROM (not shown) that stores the basic program and an internal RAM (not shown) that stores the processing data are provided. Be prepared.

The buffer 14 of the CPU 11 serves as an external ROM 16 for expansion, an external RAM 17, and an input / output unit for other devices via a bus line 15 through which control signals, address data, processing data, etc. are transmitted. A functional GA (gate array) 18 is connected.

On the other hand, the CPU 11 is driven on the basis of a low-voltage power supply of 3V, and this low-voltage reference power supply line is connected to the booster 13 and to the buffer 14 via the low-voltage gate GL. Connected. Further, the 5V high-voltage power supply line that has been boosted through the booster 13 and passed through the regulator 19 is connected to the buffer 14 through the high-voltage gate GH.

Then, a boosting control signal for the booster 13, a power supply control signal to each of the high and low voltage gates GL and GH for selectively connecting the reference power supply line or the high voltage power supply line to the buffer 14, and each of the buffer 14 Any access control signal for setting the access mode to the external device is output from the control unit 12 according to the external device to be accessed. Here, the external ROM 16, the external RAM 17, and the GA 18 are all high-voltage drive devices.

That is, in the small-sized electronic computer having the above-mentioned configuration, when the CPU 11 performs control operation without accessing the external device via the buffer 14, it does not access the high voltage driving device. The booster control signal for the booster 13 is not output from the controller 12 and the power supply control signal is set to "1".

Then, the 3V reference voltage signal is supplied to the CPU 11 and each part of the low voltage drive circuit via the low voltage gate GL, which normally enables the power saving operation by the 3V low voltage reference voltage signal. Be done.

On the other hand, when data is accessed from the control unit 12 via the buffer 14 to, for example, the external ROM 16 or the external RAM 17, both the external ROM 16 and the external RAM 17 are high voltage drive devices. The control unit 12 outputs a boost control signal to the booster 13, and the power supply control signal is set to "0".

Then, the high voltage signal of 5V obtained from the booster 13 via the regulator 19 is supplied to the buffer 14 via the high voltage gate GH, and the data access set according to the access control signal from the control unit 12 is performed. The data is supplied to the ROM 16 or the RAM 17 and the data is written in or read from the memory address addressed by the control unit 12.

Therefore, according to the small-sized electronic computer having the above configuration, the low voltage (3V) → high voltage (5V) booster 13 is provided inside the low voltage (3V) driven CPU 11, and the high voltage driven external ROM 16 and At the time of data access to the RAM17, the low-voltage and high-voltage gates GL and GH are turned on / off respectively so that the high-voltage power source can be selectively obtained. It is possible to operate by supplying a high-voltage power supply signal boosted only to it, and it is possible to achieve high functionality without hindering power saving.

[0019]

[Effect of the device]

 As described above, according to the present invention, the voltage generating means for generating a plurality of voltages, the plurality of devices driven by different voltages, and the voltage generating means for generating a voltage according to the device to be accessed among the plurality of devices are generated. Since it is configured to include a voltage selection means for selecting a voltage to be used, it is possible to save power even when high functionality is achieved such as mounting a large capacity memory.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a small electronic computer according to an embodiment of the present invention.

[Explanation of symbols]

11 ... CPU, 12 ... Control part, 13 ... Booster, 14 ... Buffer, 16 ... External ROM, 17 ... External RAM, 18 ...
GA (gate array), 19 ... Regulator, GL ... Low voltage gate, GH ... High voltage gate, INV ... Inverter.

Claims (1)

Claims for utility model registration 1. A voltage generating means for generating a plurality of voltages, a plurality of devices driven by different voltages, and the voltage generating means according to a device to be accessed among the plurality of devices. A small electronic calculator, comprising: a voltage selection unit that selects a voltage generated by the computer.