JPH05108217A - Electronic equipment - Google Patents

Abstract

PURPOSE:To provide an electronic equipment capable of controlling the start or suppression of resume processing corresponding to the state of a battery and surely realizing a resume function as the one capable of surely performing the resume processing to restore the electronic equipment to a state where a power source is disconnected last time when the power source is applied. CONSTITUTION:The electronic equipment driven by the battery is composed of a voltage detecting means 11 which detects the voltage of battery 10, a judging means 12 which judges whether or not the voltage detected by the voltage detecting means 11 is higher than a prescribed value, and a control means 13 which stands by until the voltage of the battery 10 goes to the prescribed value when it is judged that the voltage of the battery 10, goes less than the prescribed value when the power source is applied, and performs the resume processing to restore the electronic equipment to the state where the power source is disconnected last time when it is judged that the voltage of the battery 10 exceeds the prescribed value by the judging means 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device which is driven by a battery and which, when the power is turned on, can surely perform a resume process for returning to the state when the power was last turned off.

In recent years, for example, handheld computers,
BACKGROUND ART Battery-powered devices (hereinafter referred to as “battery-powered devices”) such as laptop computers and palmtop computers have been remarkably spread, and have come to be used on a daily basis.

In such a battery drive device, in order to suppress the discharge of the battery as much as possible and ensure a long-term operable state, turning on / off of the power source is often repeated. Therefore, when the power is turned on, it is desired to restore the state at the time when the power was last turned off so that it can be continuously used.

[0004]

2. Description of the Related Art Conventionally, a battery-operated device equipped with a resume function is known. Resume function saves predetermined information when power is turned off (this is called "suspend processing"), and restores the predetermined information saved by suspend processing when power is turned on (this is called "resume processing"). This is a function that allows the device to be used in the state before the last power-off.

In the conventional battery-operated device, such resume processing is performed regardless of the remaining capacity of the battery. Therefore, the resume process may be performed in a state where the battery has almost no remaining capacity.

In such a case, the voltage of the battery drops to a voltage at which the device cannot be driven during the resume process, the contents of the memory in the device are destroyed, or the resume process is performed only halfway. In addition, there is a drawback that the resume process cannot be normally performed at the next power-on.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an electronic device capable of controlling the start or inhibition of the resume process according to the state of a battery and realizing a reliable resume function. The purpose is to do.

[0008]

As shown in principle in FIG. 1, an electronic apparatus according to the present invention is an electronic apparatus driven by a battery 10, and includes voltage detection means 11 for detecting the voltage of the battery 10. Judgment means 12 for judging whether or not the voltage detected by the voltage detection means 11 is larger than a predetermined value.
When the determination unit 12 determines that the voltage of the battery 10 is equal to or lower than a predetermined value when the electronic device is turned on, the electronic device waits until the voltage of the battery 10 reaches the predetermined value. When the judging means 12 judges that the voltage of the battery 10 has become equal to or higher than a predetermined value, it comprises a control means 13 for performing a resume process for returning the electronic device to the state before the previous power-off.

[0009]

According to the present invention, as shown in FIG. 2, when the power is turned on, it is first checked whether or not the voltage of the battery 10 is below a predetermined value (step S1), and it is determined that the voltage is below the predetermined value. Then, the operation interruption process is performed (step S
2). Therefore, in this case, the resume process is not performed. After that, the process returns to step S1
While repeatedly executing 1 and S2, a standby state is entered.

In the standby state, the voltage of the battery 10 becomes higher than a predetermined value due to, for example, charging, and if it is determined that the resume process is executed (step S3). That is, the predetermined information saved at the previous power-off is restored and the state of the electronic device is returned to the state before the power-off.

As a result, the operation is started from the continuation of the previous power-off.

As described above, when the voltage of the battery 10 is equal to or lower than the predetermined value, the resume process is suppressed and the battery 10
Since the resume processing is performed only when the voltage of the above is higher than the predetermined value, it is possible to prevent the voltage of the battery from dropping to a voltage at which the device cannot be driven during the resume processing, destroying the contents of the memory and performing the resume processing. It is possible to avoid the situation where the process is only performed halfway.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows the configuration of an embodiment of the electronic equipment of the present invention. In the following description, the same or corresponding parts as those in FIG.

In the figure, 20 is a CPU (central processing unit). The CPU 20 controls the entire electronic device. A clock controller 21 is connected to the CPU 20.

The clock controller 21 is the CPU
It controls the clock supplied to 20. That is,
A high-speed or low-speed clock is selectively supplied to the CPU 20 according to a control signal from the CPU 20. This allows
The CPU 20 can operate at high speed in a predetermined case and at low speed in other cases.

A system bus 22 is output from the CPU 20 and is connected to various I / Os (memory, various controllers, etc.) via the system bus 22. Through the system bus 22, the CPU 20 and I
The operation of this electronic device is controlled by exchanging data with / O.

This electronic device has a ROMA as a memory.
23, ROMB24, RAM25 and memory card 26
Is provided. The allocation of these memories in the address space is shown in FIG.

ROMA 23 and ROMB 24 are read-only memories, and store an input / output control program (I / O) and an operating system (DOS), respectively.

The RAM 25 is a random access memory, and has a work area of the OS, a suspend save area,
It is used as a display memory and other work areas. The RAM 25 is backed up by a battery (not shown).

The memory card 26 is, for example, a portable I
It is realized as a C card and can be inserted into the electronic device and used as a memory. The memory card 26 having various memory capacity has become available, a predetermined address space (E0000 _H ~
EFFFF _H ) can be exchanged for use. This address space has a bank structure, and the memory card 26 is used as each bank memory.

The system bus 22 has a memory controller 27, an interrupt controller 28, and a DMA2.
9, display controller 30, internal modem 31, magnetic card reader 32, RS232C interface A33, R
S232C interface B34, power supply controller 3
5 and the voltage detection circuit 11 are connected.

Since the configuration and operation of each of the above-mentioned elements are not directly related to the gist of the present invention, they will be briefly described below. The memory controller 27 includes ROMA23 and ROMB2.
4, controlling the writing / reading of data to / from the RAM 25 and the memory card 26. The interrupt controller 28 controls an interrupt to the CPU 20. The DMA 29 controls data transfer between the memory and other I / O.

The display controller 30 controls the display of a display (not shown). The built-in modem 31 performs modulation / demodulation of signals when communicating with the outside. The magnetic card reader 32 reads data from, for example, a magnetic stripe provided on a card. RS23
The 2C interface A33 and the RS232C interface B34 control transmission / reception of data to / from an external device.

The power supply controller 35 performs control for designating one of a plurality of voltage types of the power supply circuit 36 to be output. This makes it possible to supply only the necessary type of power and prevent the battery 10 from being unnecessarily discharged.

The power supply circuit 36 is supplied with electric power from the battery 10 to generate a voltage necessary for operating the electronic equipment and supplies it to each circuit of the electronic equipment.

Reference numeral 10 denotes a battery, which is a rechargeable battery such as a nickel-cadmium battery or a lithium battery. The output of the battery 10 is supplied to the power supply circuit 36 and the voltage detection circuit 11.

The voltage detection circuit 11 detects the voltage of the battery, and the detection result is notified to the CPU 20. Details of the voltage detection circuit 11 will be described later.

FIG. 4 shows the address space of the memory of the present electronic equipment and the allocation state of each memory, and the suspend save area (9) is directly related to the features of the present invention.
8000 _{H to} 9FFFF _H ) are provided in the RAM 25.

This suspend area is an area for saving predetermined data during the suspend process. Here, the suspend process means that when the power is turned off, the contents of the OS work area, the contents of the CPU 20, the display controller 30, the memory controller 27, the interrupt controller 28, and other registers included in the peripheral LSI are stored in the battery-backed memory area. This is the process of saving. The details of this suspend processing will be described later.

Each data saved in the suspend save area by this suspend processing is returned to the original memory area, register or the like when the power is turned on. This is called resume processing. The details of this resume processing will also be described later.

FIG. 5 is a diagram showing the configuration of the first embodiment of the voltage detection circuit 11 shown in FIG. In the figure, 20
Is a CPU described above, and 11 is an A / D converter 110 as a voltage detection circuit.

Here, the function of the A / D converter 110 will be briefly described. This A / D converter 110 has a plurality of analog signal input terminals (only one input terminal IN is shown in the figure), and this input terminal IN
The voltage from the battery 10 is divided by resistors R1 and R2 to be supplied to.

The A / D converter 110 also includes
CPU20 to A / D converter clock ADCCL
The K, A / D converter address ADCADR, and A / D converter chip select ADCCS signals are supplied.

A / D converter chip select ADCC
The S signal is a signal for enabling the A / D converter 110. A / D converter address AD
The CADR signal is a signal instructing which of the plurality of input terminals to select. The A / D converter clock ADCCLK signal is the A / D converter address A
It is a signal that gives the timing of taking the DCADR signal into the A / D converter 110 and the timing of outputting the data from the output terminal DO.

The A / D converter 110 also includes
From a clock generation circuit (not shown), a clock signal SCL
K is supplied. This clock signal S
CLK is a signal for operating the circuit inside the A / D converter 110.

Further, a reference voltage REF is supplied to the A / D converter 110 from a constant voltage generating circuit (not shown). A / D converter 110
Is adapted to convert the input voltage into a digital value with reference to this reference voltage REF. The constant voltage generating circuit is a well-known circuit that receives a voltage from the battery 10 and generates a constant voltage lower than the battery voltage.

The input voltage value converted into a digital value by the A / D converter 110 is the clock signal ADCCLK.
The data is output from the output terminal DO and supplied to the CPU 20 in a 1-bit serial manner in synchronism with.

The CPU 20 receives the data output from the output terminal DO, recognizes the battery voltage, and checks whether or not the voltage is below a predetermined value (see step S1 in FIG. 2).

FIG. 6 is a diagram showing the configuration of the second embodiment of the voltage detection circuit 11 shown in FIG. In the figure, 20
Is a CPU described above, and 11 is a comparator 111 as a voltage detection circuit.

Here, the function of the comparator 111 will be briefly described. The comparator 111 has one analog signal input terminal IN, and this input terminal IN
The voltage from the battery 10 is divided by resistors R1 and R2 to be supplied to.

The comparator 111 also has a built-in reference voltage generation circuit 112. The reference voltage generation circuit 112 is provided with a power supply VC supplied from the power supply circuit 36.
C is input to generate a voltage for comparison with the signal input from the input terminal IN. The result of comparison by the comparator 111 is output from the output terminal OUT as a “1” or “0” signal and supplied to the CPU 20.

The CPU 20 receives the signal output from the output terminal OUT and checks whether or not the battery voltage is equal to or lower than a predetermined value (reference voltage) (see step S1 in FIG. 2).

Next, the operation of the electronic apparatus according to the present invention having the above structure will be described.

When the power of this electronic device is turned off, a suspend process is performed. FIG. 7 shows details of the suspend process.

In the suspend process, first, the CPU register is saved (step S11). That is, CP
The contents of a predetermined register in U20 are stored in RAM25.
Stored in the suspend save area of. Next, the stack pointer is saved (step S12).
Here, the stack pointer is provided in the RAM 25 and indicates the stack currently in use.

Next, the interrupt mask is set (step S13). This interrupt mask is set to prohibit interrupts and to perform the following processing quickly.

Next, the registers inside the memory controller 27 are saved (step S14), and the registers inside the interrupt controller 28 are saved (step S1).
5), the saving of registers inside the DMA 29 (step S16) and the saving of registers inside the display controller 30 (step S17) are sequentially executed.

Then, the clock controller 21 is controlled to set the clock of the CPU 20 to be high speed (step S18). Below, CPU with high-speed clock
20 will operate.

Next, the control status of the internal modem 31 is saved (step S19), and the status of the power supply controller 35 is saved (step S2).
0). Next, the bank of the memory card 26 is saved (step S21). That is, the number of the currently selected bank is saved. Next, the magnetic card reader 3
The control status 2 is saved (step S22).

Next, the RS232C interface A3
Save setup for step 3 (step S23), RS2
The setup of the 32C interface B34 is saved (step S23). Here, the setup data is, for example, speed information, data word length, information regarding the presence / absence of a parity bit.

Next, the setting values of the peripheral LSI are saved (step S25). This is a process of saving data contained in an unillustrated LSI for realizing various functions.

Next, the NMI vector is saved (step S26). Here, the NMI vector is information indicating the entry address of the processing routine of the interrupt non-interruptible interrupt (NMI). Then RAM25
Save the contents of the OS work area inside (step S
27), set the suspend bit (step S2)
8). This suspend bit is a bit indicating whether or not suspend processing has been performed, and is referred to during resume processing.

After the series of processes described above is completed, a power-off process is performed (step S29). That is, by controlling the power supply controller 35, the output of the power supply circuit 36 is turned off, and the power supplied to each part of the electronic device is cut off.

Next, when turning on the power of this electronic apparatus,
Resume processing is performed. FIG. 8 shows details of the resume process.

In the resume process, first, before restoring the data saved by the suspend process, various initial checks are performed to ensure the validity of the electronic device.

First, the operation check of the CPU 20 is performed (step S31). Next, the peripheral LSI is initialized (step S32). This is a process of initializing an LSI (not shown) for realizing various functions.

Next, the RAM 25 is checked (step S33). RAM25 is read /
It is a check whether writing is possible. Then, the memory controller 27 is initialized (step S3).
4) The display controller 30 is initialized (step S35). As a result, the read / write operation of the RAM 25 and the display operation on the display can be performed.

Then, the sum check of the ROMs 23 and 24 is performed (step S36). This is ROM2
This is a process of adding all the data in 3 and 24 and checking whether the result is the same as the data prepared in advance. This ensures the legitimacy of the ROMs 23 and 24.

Then, the resume processing flag is set (step S37). This flag is used for recognizing that the processes of steps S38 and S39 described below are being performed. That is, when an interrupt occurs while the resume processing flag is set, special processing (details are omitted) is performed.

Then, each I / O is tested and initialized (step S38). That is, the above-mentioned I
I / O other than / O will be tested and initialized. Then, the resume stack is set (step S39). That is, a stack is formed for executing the resume process described below. Then, the resume processing flag is cleared (step S40).

The initial check process is completed by the above process, and the process of restoring the data previously saved by the suspend process is started. Although not shown in the figure, if the suspend bit is not set, that is, if the suspend process is not performed when the power is turned off, the following restore process is not performed and step S55 is performed.
The process branches to and the interrupt mask is released, and the process returns from this resume processing routine.

In the following restore process, the restore is performed in the reverse order of the case of saving in the suspend process. That is, the OS work area is restored (step S41) and the NMI vector is restored (step S4).
2) The registers of the display controller 30 are sequentially restored (step S43), and then the predetermined data is displayed on the display (step S44).

Next, the setting value of the peripheral LSI is restored (step S45), the bank of the memory card 26 is restored (step S46), the setup of the RS232C interface A33 is restored (step S47),
RS232C interface B34 setup restore (step S48), DMA29 register restore (step S49), interrupt controller 28
Of the registers of the memory controller 27 (step S50) and the registers of the memory controller 27 (step S5).
1), setup of stack pointer (step S5)
2) and the restoration of the registers of the CPU 20 (step S53) are sequentially executed.

Then, the resume completion flag is set (step S54), the interrupt mask is released (step S55), and then the process returns from this resume processing routine.

When the above resume processing is completed, CP
The control of U20 is passed to the position where it was being executed when the power was cut off, and execution is started from the continuation of when the power was cut off.

As described above, according to this embodiment, when the voltage of the battery 10 is equal to or lower than the predetermined value, the resume process is suppressed to enter the standby state, and when the voltage of the battery 10 becomes equal to or higher than the predetermined value. Since the resume process is performed, it is possible to prevent the voltage of the battery from dropping to a voltage at which the device cannot be driven during the resume process. It can be avoided.

[0067]

As described in detail above, according to the present invention,
It is possible to provide an electronic device that can control the start or inhibition of the resume process according to the state of the battery and can realize a reliable resume function.

[Brief description of drawings]

FIG. 1 is a principle diagram of an electronic device of the present invention.

FIG. 2 is a flowchart showing an operation of the electronic device of the invention.

FIG. 3 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 4 is a diagram showing allocation of each memory used in an embodiment of the present invention in an address space.

FIG. 5 is a diagram showing a configuration of a first embodiment of a voltage detection circuit according to the embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a second embodiment of the voltage detection circuit according to the embodiment of the present invention.

FIG. 7 is a flowchart showing a suspend process according to the embodiment of this invention.

FIG. 8 is a flowchart showing a resume process according to the embodiment of this invention.

[Explanation of symbols]

 10 Battery 11 Voltage Detection Means (Voltage Detection Circuit) 12 Judgment Means (CPU) 13 Control Means (CPU) 20 CPU

Claims (4)

[Claims] 1. In an electronic device driven by a battery (10), voltage detection means (11) for detecting the voltage of the battery (10).
A judging means (12) for judging whether the voltage detected by the voltage detecting means (11) is larger than a predetermined value, and the judging means (1) when the power of the electronic device is turned on.
When it is determined in 2) that the voltage of the battery (10) is less than or equal to a predetermined value, the battery (10) waits until the voltage reaches a predetermined value, and the determination means (12) determines the voltage of the battery (10). The electronic device comprises a control means (13) for performing a resume process for returning the electronic device to the state before the previous power-off when it is determined that is equal to or more than a predetermined value. 2. The electronic device according to claim 1, wherein the voltage detection means (11) is an analog-digital converter. 3. The electronic device according to claim 1, wherein the voltage detecting means (11) is a comparator. 4. When the power is turned on, the voltage of the battery (10) is inspected, and if the voltage is equal to or lower than a predetermined voltage, a resume process is started to restore the electronic device to the state before the last power-off. The resume system is characterized by suppressing the above and waiting until a predetermined voltage is reached.