JPH03228109A - Electronic device - Google Patents

Abstract

PURPOSE:To enable low energy consumption driving together with a high-speed processing operation by providing a clock control circuit to switch a clock to a high frequency clock according to the detection signal of specified key pressure from a keyboard control part and to switch the clock to a low frequency clock according to a specified signal to be generated from a processing part. CONSTITUTION:When an electronic device is composed of a clock generating circuit 1, 4-bit binary counter 2 and clock control circuit 3, a clock supplying circuit supplies the high frequency clock or the low frequency clock to a processing part 8. According to the detection signal of the specified key pressure from a keyboard control part 10, the clock control circuit 3 switches the clock, which is supplied to the processing part 8, to the high frequency clock and according to the specified signal to be generated from the processing part 8, the clock is switched to the low frequency clock. Thus, when a high-speed operation is required, the high frequency clock is supplied to the processing part so as to execute the high-speed operation, and in the other case, the low frequency clock is supplied so as to reduce energy consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electronic devices, and in particular, to control of clock supply in an electronic device equipped with a processing section consisting of a semiconductor integrated circuit device to which a clock is supplied and driven. properly,
The present invention relates to an electronic device that enables high-speed processing operation and low power consumption.

[Conventional technology]

Conventionally, in electronic devices, such as word processors and personal computers, which are configured with a processing section consisting of a semiconductor integrated circuit device that is supplied with a clock and driven,
The frequency of the clock supplied to the semiconductor integrated circuit device of the processing section is constant. The higher the clock frequency supplied to the semiconductor integrated circuit device in the processing section, the faster the processing operation can be performed. is often used.

Recently, high frequency clocks of 16M) Iz to 20M) tz have been used.

[Problem to be solved by the invention]

By the way, in electronic devices configured with a processing section made of a semiconductor integrated circuit device that is driven by being supplied with a lock as described above, there is no consideration given to power consumption, and it is necessary to perform high-speed processing. , a semiconductor integrated circuit device (CPU) in the processing section.

The problem is that the electronic device as a whole consumes a large amount of power because it is operated at the maximum operating clock frequency of the electronic device (RAM, etc.).

Furthermore, in recent years, electronic devices of this type have become portable and removable, such as laptop-type devices, and reducing power consumption has become a major issue.

The present invention has been made to solve the above problems.

An object of the present invention is to appropriately control the clock supply in an electronic device equipped with a processing unit made of a semiconductor integrated circuit device that is supplied with a clock and driven, thereby enabling high-speed processing operation and low power consumption driving. The purpose is to provide electronic devices.

[Means to solve the problem]

In order to achieve the above object, the electronic device of the present invention includes a keyboard including specific keys, a keyboard control section, and a processing section consisting of a semiconductor integrated circuit device supplied with tarokku and driven. A clock supply circuit that supplies a clock and a low-frequency clock, and a clock control circuit that switches to a high-frequency clock based on a detection signal of a specific key press from the keyboard control unit, and switches to a low-frequency clock based on a specific signal generated from the processing unit. It is characterized by comprising:

[Effect]

According to the above means, the electronic device includes a clock supply circuit and a clock control circuit.

The clock supply circuit supplies a high frequency clock or a low frequency clock to a processing section made of a semiconductor integrated circuit device. The clock control circuit switches the clock supplied to the processing section to a high frequency clock in response to a detection signal of a specific key press from the keyboard control section, and switches it to a low frequency clock in response to a specific signal generated from the processing section.

In this way, by providing a clock supply circuit and a clock control circuit, when high-speed processing is required, a high-frequency clock is supplied to the semiconductor integrated circuit device of the processing section to perform high-speed operation, and for other purposes. supplies a low frequency clock to reduce power consumption.

For example, as the high frequency clock, a clock having the maximum operating clock frequency of the semiconductor integrated circuit device is supplied, and a clock obtained by dividing this high frequency clock is supplied as the low frequency clock. The clock frequency is switched by determining the execution period of the processing section based on a detection signal from the keyboard control section when a specific key (for example, the execution key) is pressed, or when high-speed operation is no longer required from the processing section (for example, Switching is performed by a specific signal generated at the end of processing). Specifically, the keyboard control section makes the control signal output inactive until a specific key is pressed, and the processing section (
When the CPU, etc.) is executing a process that requires high-speed processing (
(when a specific key is pressed), outputs an activated control signal. The clock control circuit monitors the control signal of the keyboard control section, outputs a low frequency clock when inactive, and outputs a high frequency clock when activated. When the processing in the processing section is completed, in order to return to the low frequency clock again, the processing section controls the keyboard control section to make the control signal inactive at the end of processing, and changes the output of the clock control circuit to the low frequency clock again. do.

In this way, a low frequency clock is supplied except when high-speed processing of the processing section is required, so that power consumption can be reduced.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described using the drawings.

FIG. 1 is a block diagram showing the configuration of essential parts of an electronic device according to an embodiment of the present invention. In FIG. 1, 1 is a clock generation circuit that generates a high frequency clock (high speed clock φ) having the maximum operating clock frequency of a semiconductor integrated circuit device, and 2 is a 4-bit binary counter. A high-speed clock φ is input to the CLK terminal of this 4-bit binary counter 2, and a clock frequency-divided by 4 is output as a low-frequency clock (low-speed clock φA). For example, as the clock generation circuit 1, a high speed clock φ and a low speed clock φ1
If a lock generation circuit capable of generating both of the following is used, the 4-bit binary counter 2 may not be provided.

Further, 3 is a clock control circuit. The clock control circuit 3 includes an AND circuit 4. Inverter circuit 5゜AND circuit 6
．． and an OR circuit 7. Reference numeral 8 is a microprocessor (hereinafter abbreviated as CPU) of a semiconductor integrated circuit device (LSI), and reference numeral 9 is a control processing unit consisting of an image processing LSI and a peripheral LSI that performs high-speed data input/output processing. 10 is a keyboard control unit;
Although not shown, a unit (CPU 8, control processing unit 9) scans the keyboard to detect key suppression signals and processes input data.
control the supply to the When a specific key (execution key) is pressed, the keyboard control section 10 detects this and sets the output signal A from the keyboard control section 10 to a high level. 11 is a selector circuit, 12 is a data bus, 13 is an address bus, and 14 is a system clock bus. The selector circuit 11 has an address bus 13 and a data bus 12.
Detects the specific data sent through the keyboard controller 10 and supplies a detection signal B to the keyboard controller 10. The specific data here is, for example, data sent from the CPU 8 at the end of processing in the processing section. When the keyboard control section 10 receives the detection signal B from the selector circuit 11, the keyboard control section 10 sets the output signal A to a low level.

Next, a description will be given of the clock supply operation of the electronic device configured in this manner.

When the user of the electronic device is normally operating the keyboard, the output signal A of the keyboard control section 10 is at a low level. In this case, the clock control circuit 3 selects the logic (A·φA) on the AND circuit 4 side, and outputs the 5 low-speed clock φ1 as the clock signal φ. When data input from the keyboard is completed, the user then presses a specific key (execute key) on the keyboard to instruct execution of processing. When a specific key is pressed, the keyboard control unit 2 detects this and sets the output signal A to a high level. As a result, in the clock control circuit 3, the logic (A·φ) on the AND circuit 6 side is selected, and the high speed clock φ is outputted as the clock signal φ. In this way, the clock signal φ outputted from the lock control circuit 3 is connected to the clock supply terminal CL of the CPU 8.
The clock signal is also sent to the system clock bus 14, and then supplied to the control processing section 9 via the system clock bus 14. Therefore, the CPU 8 and the control processing unit 9 are supplied with the high-speed clock φ and operate at the same time as the start of processing, so that the processing operations are executed at high speed. C
When the processing is completed in the PU 8 and the control processing unit 9,
The CPU 8 sends an address and specific data for selecting the selector circuit 11 via the address bus 13 and the data bus 12. When this specific data is sent, the selector circuit 11 detects the sending of this specific data and outputs a detection signal B. The detection signal B of the selector circuit 11 is sent to the keyboard control section 10, and the keyboard control section 10 sets the output signal A to a low level. As a result, the clock signal φ3 supplied to the CPU 8 and the control processing section 9 is returned to the low-speed clock φ.

In this way, when the user is operating the keyboard, C
The processing section including the PU 8 and the control processing section 9 operates at a low speed clock and performs idle operations, but when the execution key is pressed and the processing section actually performs processing,
The supplied clock is switched to a high-speed clock,
The processing unit performs processing at high speed. In the processing section, when the processing is completed, the CPU 8
The address and specific data for selecting the selector circuit 11 are sent to the address bus 13 . data bus 1
Output to 2. By sending this address and specific data, the selector circuit 11 takes in the specific data,
Outputs detection signal B. This detection signal B is input to the keyboard control section 10, and the detection signal B is input to the keyboard control section 10.
makes the output signal A low level. This allows the CPU
The clock supplied to the processing units including 8 and control processing unit 9 returns to the low-speed clock.

FIG. 2 is a timing chart showing an example of signal waveforms of each part of the electronic device shown in FIG. In the timing chart of FIG. 2, a period ta is a period during which the keyboard is being operated. During the period ta, the clock signal φ supplied to the processing units including the CPU 8 and the control processing unit 9 is the low-speed clock φ8. The next period tb is a period in which the execution key is pressed, the supplied clock signal φ is set as the high-speed clock φ, and the processing units of the CPU 8 and the control processing unit 9 perform high-speed processing. Further, during the period tc, the processing of the processing section is completed and the clock signal φ is supplied again.

This is the period when the slow clock was used. In this way, the clock signal φ supplied to the processing section can be appropriately switched between a high speed clock and a low speed clock depending on the state of the processing section.

FIG. 3 is a flowchart showing an outline of a processing flow in a processing section including a CPU and a control processing section.

Referring to FIG. 3, first, processing on the CPU 8 side is performed by driving a low-speed clock, and in step 31, manual key processing by keyboard operation is performed. When the manual key processing in step 31 is completed and a specific key signal such as an execution key is input in step 32, the clock supplied by the clock control circuit is switched to a high speed clock, and the process from step 33 is performed. High-speed data processing begins. This high-speed data processing causes the processing at step 34 to be executed. In the process execution of step 34, if necessary, coprocessor LS1. Image processing LSI
, a peripheral LSI, etc., performs a series of high-speed processing such as floating point arithmetic processing, 1 image processing, and high-speed data input/output processing. Once these processes are complete,
Control of the process is returned to the CPU, and at the end of the process, in step 35, the selected address and specific data of the selector circuit are sent. When the selected address and specific data of the selector circuit are sent to the address bus and the data bus through the process of step 35, the selector circuit detects this, sends out the detection signal B, and uses the output signal A of the keyboard control section to Since the clock control circuit is controlled to switch the supplied clock signal to a low-speed clock, low-speed data processing starts from step 36.

Then, due to such low-speed data processing, the manual key processing of the keyboard operation in step 31 is performed again. Such a series of processing is performed, and processing in the electronic device is continued.

As described above, according to this embodiment, a clock control circuit is provided, and when a keyboard is operated, a low frequency clock is supplied to reduce power consumption, and when an execution key is pressed, an instruction to execute a process is issued. To perform processing operations at high speed by supplying the maximum operating clock frequency only when a CPU and a control processing section require high-speed processing. As a result, in an electronic device including a processing section made of a semiconductor integrated circuit device that is supplied with a clock and driven, the clock supply can be appropriately controlled, and high-speed processing operation and low power consumption can be achieved.

The present invention has been specifically explained above based on examples, but
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof.

〔Effect of the invention〕

As explained above, according to the present invention, except when it is necessary to operate the processing unit including the CPU at high speed by pressing a specific key such as the execution key, the processing unit including the CPU is operated at low speed using a low frequency clock. Electronic devices can perform high-speed processing operations and have the effect of reducing power consumption.

[Brief explanation of drawings]

1 is a block diagram showing the configuration of main parts of an electronic device according to an embodiment of the present invention; FIG. 2 is a tuning chart showing an example of signal waveforms of each part of the electronic device of FIG. 1; FIG. 3 is a flowchart showing an outline of a processing flow in a processing section including a CPU and a control processing section. In the figure, 1... Clock generation circuit, 2... 4-bit binary counter, 3... Clock control circuit, 4, 6...
・AND circuit, 5... Inverter circuit, 7... OR circuit, 8... Microprocessor (CPU), 9...
- Control processing unit, 10...Keyboard control unit, 11...
- Selector circuit, 12...data bus, 13...address bus, 14...system clock bus. Bacterial paper 2 [1l -ta +tb +tc - 3rd, 8

Claims (1)

[Claims] 1. A keyboard including specific keys, a keyboard control section,
In an electronic device equipped with a processing unit consisting of a semiconductor integrated circuit device that is supplied with a clock and driven, a clock supply circuit that supplies a high frequency clock and a low frequency clock, and a detection signal of a specific key press from a keyboard control unit . A clock control circuit that switches to a high frequency clock and switches to a low frequency clock based on a specific signal generated from a processing section. 2. The specific key is a key that instructs the processing unit to execute processing, and the specific signal generated from the processing unit is a detection signal for sending specific data that is generated when the processing unit finishes processing. The electronic device according to claim 1. 3. A keyboard including specific keys, a keyboard control section,
A clock supply circuit that switches between a high frequency clock and a low frequency clock according to a control signal and supplies the clock to the processing section in an electronic device including a processing section consisting of a semiconductor integrated circuit device to which a clock is supplied and driven; An electronic device comprising: a clock control circuit that instructs the processing section to execute processing from a control section, generates a control signal only while the processing section is executing the processing, and drives the processing section with a high-frequency clock.