JPH09319472A - Information processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unnecessitate the alteration of an application program(AP) by performing a power saving operation by judging whether key scanning is continuously performed or not according to whether the return address of the AP is the same or not. SOLUTION: When both the return addresss of a stack and the data of a work 1 in a RAM 5 are coincident with each other, the data of a work 2 are counted up. Namely, these data are counted as one time. At such a time, since the matching between both the return address of the stack and the value of the work 1 means calling from the same position in the AP, the data of the work 2 mean the number of times of continuous key scanning and correspond to the length of a key waiting state. Next, when the value of the work 2 does not exceed a set value N, the key scan is repeated and the number of times of continuous key scanning is counted. When the value of the work 2 exceeds the set value N, a power save signal is outputted to a power control circuit 3 and a processor is switched to a power save mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus, and more particularly to an information processing apparatus suitable for application to a battery-operated small-sized information processing apparatus that requires a power saving system.

[0002]

2. Description of the Related Art Conventionally, a program installed in a small-sized information processing device that operates on a battery is designed in consideration of power saving (power saving) on the assumption of battery operation. That is, a program for switching to the power save mode when waiting for a human operation is incorporated in the application program itself, so that power consumption during the waiting time is suppressed and the battery lasts longer. Meanwhile, in recent years,
Although the scale of application programs tends to be large, many large-scale application programs such as Japanese word processing programs and spreadsheet programs are not designed on the assumption that they operate on a battery.
That is, the power save processing program is not incorporated in the application program itself.

[0003]

If a large-scale application program that is not based on the above-mentioned battery operation is installed in a battery-operated small-sized information processing apparatus, the power saving operation is not performed, and the battery life is shortened. there were. In addition, it is not easy to modify such a large-scale application program to accommodate a battery-operated small-sized information processing device because of the large scale of the program. Therefore, for power saving when a large-scale application program is installed in a small-sized information processing apparatus, a method of switching to the power save mode in the system program portion is adopted only when waiting for a key. However, this method is not suitable because many application programs operate while performing key scanning. That is,
Power saving in the key scan has a drawback that a program that operates while checking the cancel (stop) key is stopped or the operation of the program becomes slow. To avoid this, it is necessary for the application program to permit or prohibit power saving, but as described above, it is difficult for a large-scale application program.

The present invention has been made to solve the above-mentioned conventional drawbacks, and automatically and appropriately performs power saving processing without modifying the application program and without impairing the performance of the application program. An object of the present invention is to provide an information processing device capable of performing the above.

[0005]

According to an information processing apparatus of the present invention for solving the above problems, a return address of an application program when the application program calls a key scan routine is stored in a storage device, and then the application program is stored. Continuous key scan determining means for determining whether or not the application program continuously calls a key scan routine by comparing the return address of the application program when the subroutine calls the data of the storage device. And a power save instruction means for counting the number of consecutive key scan routine calls based on the judgment result of the continuous key scan judgment means and outputting a power save signal when the counted number exceeds a set value, and the power save instruction. As well as transition to the power saving mode by a signal, characterized by comprising a power control circuit to cancel the power-saving mode by an interrupt signal from the external hardware.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
A description will be given with reference to an embodiment shown in FIG. FIG. 1 shows a block diagram of a small-sized information processing apparatus according to an embodiment of the present invention.
This small-sized information processing device includes a central processing unit (CPU) 1
And a peripheral circuit 2 and a power control circuit 3. The CPU 1 and the peripheral circuit 2 are general ones used in microcomputers and personal computers. The peripheral circuit 2 is a ROM
4 and RAM 5, the system program and the application program are stored in the ROM 4 or the RAM 5. The power control circuit 3 is for performing power save and cancellation of the power save mode, stops the clock to the CPU 1 based on the power save signal from the CPU 1 (that is, shifts to the power save), and also from the external hardware. A circuit for restarting (that is, canceling power save) triggered by an interrupt is provided. The factors of the external hardware interrupt include, for example, “key”, “timer”, “serial port” and the like.

The information processing apparatus of the present invention stores the return address of the application program when the application program calls the key scan routine in the storage device, and stores the return address of the application program when the application program subsequently calls the subroutine. A continuous key scan judging means for judging whether or not the application program continuously calls the key scan routine by comparing the return address with the data in the storage device, and the judgment result of the continuous key scan judging means. Based on the above, the number of consecutive key scan routine calls is counted, and when the counted number exceeds the set value, power save instruction means for issuing a power save signal and the power save mode are entered by the power save signal. As well as, and a power control circuit to cancel the power-saving mode by an interrupt signal from the external hardware.

The return address detecting means required in the above continuous key scan determining means will be described. When an application program performs a key scan, it is common to use a method called a subroutine call.
The subroutine call sets the return address in the stack memory and jumps to the key scan routine. In this embodiment, the method of the subroutine call is used. R when detecting the return address in this embodiment
The status of the stack memory (hereinafter simply referred to as a stack) in the AM5 is shown in FIG. Further, FIG. 3 shows a flowchart of the return address detection processing for correctly detecting the return address of the application program in either case of FIG. 2 (a) or FIG. 2 (b).

FIG. 2A shows the status of the stack when the application program uses only a lower-level routine such as a key BIOS (a program that is in charge of basic processing in key processing) as a key scan routine. In this case, since the return address is always at the top (5-A) of the stack, it is easy to detect the issue source address. FIG. 2B shows the state of the stack when the application program uses a higher-level routine such as an event manager (a routine that manages event occurrence) and the event manager calls the key BIOS. In this case, the address at the top (5-A) of the stack is always the same address as the event manager is calling the key BIOS. Therefore, in order to detect the issuer address (the return address of the application program), it is necessary to look at the return address at the back (5-B) of the stack. In order to be able to deal with various application programs, the situation of FIG.
It is necessary to be able to deal with any of the situations in (b). Since the event manager is a kind of system program, its address can be known in advance regardless of the application program. Therefore, FIG.
Whether the situation of (a) or the situation of FIG. 2 (b) is determined by whether or not the address at the top (5-A) of the stack is the address of the event manager. Therefore, it is preferable to detect the return address according to the flowchart shown in FIG. That is, first, the top of the stack (5-
The data of A) is stored in the pointer (stack pointer) (step S1). Next, the contents of this pointer are judged (S2). Contents of pointer (top of stack (5
Address in (A)) is different from the address of the event manager (in the case of "other address"), the address at the beginning (5-A) is determined to be the return address. When it is the same as the address of the event manager, the address at the back (5-B) of the stack is determined as the return address (and the address at the stack (5-B) is stored in the pointer (S3)).

FIG. 4 shows an example of the power saving instruction means described above.
It is shown in the flowchart. In this embodiment, "work area 1" and "work area 2" of RAM 5 are used. When the application program calls the key scan routine, the return address of the application program at that time (the stack (5
-A) or the return address on the stack (5-B) in FIG. 2B) and "work area (hereinafter called work)"
1 "data is compared (step P1).

When both the return address of the stack and the data of "work 1" match in step P1, the data of "work 2" is incremented (+1) (P2). That is, it is counted as one time. Note that "work 2" is used as a counter. The fact that both the return address of the stack and the value of "work 1" match means that the call is from the same position in the application program, so the data of "work 2" (that is, the count number) is continuous. It means the number of key scans and corresponds to the length of the key waiting state. Next, the value of the "work 2" is compared with a certain set value N that is appropriately determined (P3). If the value of "work 2" does not exceed the set value N, the key scan is repeated and the number of continuous key scans is counted as described above. When the value of "work 2" exceeds the set value N, a power save signal is output to the power control circuit 3 to switch to the power save mode (P4).

When a key input interrupt, a timer input interrupt, a serial input interrupt, etc. occur, the power control circuit 3 releases the power save mode by the interrupt signal.

In step P1, if the return address of the stack and the data of "work 1" do not match, it means that the call is made from a different position in the application program. 1 ”(P5), and the value of“ work 2 ”is initialized to 0 (P6). In the above description, the initialized state has been described. Then, after that, normal processing is performed without power saving.

The set value N for switching to the power save mode is important for performing an appropriate power save operation, but this set value N is a key scan of a routine that operates while checking the cancel (stop) key. It can be set appropriately by checking the maximum number of times. When the set value N for switching to the power save mode depends on the data processed by the application program, or
If it is very large, set the power save mode to 2 instead of turning it on and off, but set the CPU clock frequency to 1
The hardware may be changed to 0, and the clock frequency may be reduced stepwise according to the value of the "work 2".

The continuous key scan determining means for detecting the position (return address) of the application program when the application program calls the key scan routine is not limited to the method of the above embodiment.

[0016]

As described above, according to the present invention,
Since the return address of the application program that issued the key scan is the same, it is determined whether the key scan is continuously performed, and the power saving operation is performed based on the number of consecutive key scans. , Does not require modification of the application program,
Power saving processing can be realized on the system program side,
In addition, even if a large-scale application that does not operate on a battery is installed in a small-sized information processing device, the battery can last longer.

Further, the configuration of the present invention using the return address is extremely simple, very easy to actually apply to a small-sized information processing apparatus, and has an advantage of high practical value.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a small-sized information processing apparatus showing an embodiment of the present invention.

2A and 2B are diagrams showing an image of a stack in which an address of an application program is stored, and FIG. 2A shows a case where the application program uses only a lower routine such as a keyboard BIOS. In the case of (b), the application program uses a higher-level routine such as an event manager, and the event manager calls the key BIOS.

FIG. 3 is a flowchart of a return address detection process in which the system program detects a return address of the application program when the application program calls a subroutine of the system program in the embodiment of the present invention.

FIG. 4 is a flowchart showing a process associated with a key scan routine in the system program of the small-sized information processing apparatus of the above embodiment.

[Explanation of symbols]

 1 Central Processing Unit (CPU) 2 Peripheral Equipment 3 Power Control Circuit 4 RAM 5 ROM

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Hiroshi Masuno 5-7-1 Shiba, Minato-ku, Tokyo Inside NEC Corporation (72) Toshiharu Ikeda 1-4-4 Jomi, Chuo-ku, Osaka-shi, Osaka No. 24 within NEC Home Electronics Co., Ltd.

Claims (1)

[Claims] 1. A storage device stores the return address of the application program when the application program calls a key scan routine, and the storage device stores the return address of the application program when the application program subsequently calls a subroutine. Continuous key scan determination means for determining whether or not the application program continuously calls the key scan routine by comparing the data of the above, and the continuous key scan based on the determination result of the continuous key scan determination means. The number of scan routine calls is counted, and when the counted number exceeds a set value, a power save instruction means for outputting a power save signal, and the power save signal is used to shift to a power save mode, and an external The information processing apparatus characterized by comprising a power control circuit to cancel the power-saving mode by an interrupt signal from Douea.