JP2006025473A - Electronic apparatus and its data storage method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an electronic apparatus and its data storage method in which stored data is protected against destruction due to stoppage of operation of the apparatus caused by battery voltage drop, when data are stored in a nonvolatile memory such as an EEPROM, even if it is an electronic apparatus that does not have a backup function for battery voltage drop. <P>SOLUTION: A battery driven electronic apparatus, having nonvolatile memory for storing data, is provided with a battery voltage detecting section for comparing the battery voltage with a predetermined reference level. When an operation for storing specific data in the nonvolatile memory is performed, output from the battery voltage detecting section is checked in advance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an electronic device driven by a battery, such as a portable measuring instrument, and a data storage method in the electronic device.
More specifically, in such an electronic device, when data is stored in a nonvolatile memory such as an EEPROM, the operation of the device is stopped due to a decrease in battery voltage, and the stored data is destroyed. There is no data storage method.

  Conventionally, in an electronic device driven by a battery, the battery voltage is monitored, and when the battery voltage falls below the guaranteed operating voltage of the electronic device, the data being processed is saved in a nonvolatile memory, It has a function to stop operation (backup function).

  FIG. 5 is a configuration diagram illustrating an example of a conventional electronic device. In the figure, reference numeral 1 is a control unit for controlling various operations and the operation of the entire device, 2 is a display unit for displaying data, and 3 is a non-volatile memory for storing programs and data, such as an EEPROM and a flash memory. 4 is a battery for supplying driving power (rechargeable battery), and 5 is a battery voltage Vb compared with the operation guarantee voltage Vg of the device (actually a voltage value slightly higher than the operation guarantee voltage Vg). It is a voltage drop detection part which detects a fall.

In the apparatus shown in the figure, when the battery voltage Vb decreases as the battery 4 is consumed and falls below the operation guarantee voltage Vg, the voltage drop detection unit 5 generates a detection output Sg. Upon receiving this detection output Sg, the control unit 1 saves the contents of the memory and the registers of various devices in the nonvolatile memory 3 and shuts down the device.
Therefore, before the battery voltage Vb decreases and the driving by the battery 4 becomes impossible, it becomes possible to store the current usage state and the processing contents being executed in the nonvolatile memory 3 for backup.

Japanese Patent Application Laid-Open No. 07-020967 JP 2002-099468 A

However, in order to execute the backup operation as described above, a large storage capacity and a high processing speed are required. Due to the restrictions, such advanced backup functions cannot be installed.
In other words, in portable measuring instruments and the like, the capacity of the memory to be mounted is limited, and the processing speed of the control unit (CPU) cannot be increased so much. It is.
For this reason, when a defragmentation operation for rearranging the data stored in the non-volatile memory is executed, it takes a long time to complete the process. If the battery voltage Vb decreases during this time, the process The device shuts down midway, and the stored data cannot be read.

  The present invention eliminates the drawbacks of the conventional device as described above, and even when an electronic device does not have a backup function against a decrease in battery voltage, the battery is stored when data is stored in a nonvolatile memory such as an EEPROM. An object of the present invention is to realize an electronic device and a data storage method in the electronic device in which the operation of the device is not stopped due to the voltage drop and the stored data is not destroyed.

  In order to achieve the above object, according to claim 1 of the present invention, in an electronic device that operates by a battery and has a nonvolatile memory for storing data, the battery voltage in the battery is compared with a predetermined reference value. And a battery voltage detection unit configured to check a detection output of the battery voltage detection unit in advance when a specific data storage operation is performed on the nonvolatile memory.

  According to a second aspect of the present invention, in the electronic device according to the first aspect, the battery voltage detection unit compares the battery voltage with a predetermined reference value as required.

  According to a third aspect of the present invention, in the electronic device according to the first or second aspect, the specific data storage operation is a defragmentation operation for rearranging data stored in the nonvolatile memory.

  According to a fourth aspect of the present invention, in the electronic device according to any one of the first to third aspects, the reference value for comparing the battery voltages is set to a value larger than an operation guarantee voltage in the electronic device.

  According to a fifth aspect of the present invention, in the electronic device according to the fourth aspect, the reference value for comparing the battery voltage is an operation time necessary for executing the specific data storage operation with respect to an operation guarantee voltage in the electronic device. It is characterized in that it is set to a value with a margin for the corresponding voltage value.

  According to a sixth aspect of the present invention, in a data storage method that is applied to an electronic device driven by a battery and stores data in a nonvolatile memory, the battery stores the data when a specific data storage operation is performed on the nonvolatile memory. The data storage operation is executed only when the battery voltage is detected and the battery voltage is greater than a predetermined reference value.

  According to a seventh aspect of the present invention, in the data storage method in the electronic device according to the sixth aspect, the specific data storage operation is a defragmentation operation for rearranging data stored in the nonvolatile memory.

  According to an eighth aspect of the present invention, in the data storage method in the electronic device according to the sixth or seventh aspect, the reference value for comparing the battery voltages is set to a value larger than an operation guarantee voltage in the electronic device.

  According to a ninth aspect of the present invention, in the data storage method in the electronic device according to the eighth aspect, the reference value for comparing the battery voltage is necessary for executing the specific data storage operation with respect to the operation guarantee voltage in the electronic device. It is characterized in that it is set to a value having a margin of voltage value corresponding to a long operating time.

  As described above, when a specific data storage operation is performed on the nonvolatile memory, the battery voltage of the battery is detected in advance, and the data storage operation is performed only when the battery voltage is greater than a predetermined reference value. As a result, even when a process that stores data in a nonvolatile memory for a long time, such as a defragmentation operation, the battery is consumed during the process, and the operation of the device is stopped. Even if the electronic device does not have a backup function with respect to a decrease in battery voltage, stored data is not destroyed.

  Hereinafter, the electronic device of the present invention and the data storage method in the electronic device will be described with reference to the drawings.

  FIG. 1 is a configuration diagram showing an embodiment of an electronic device and a data storage method in the electronic device of the present invention. In the figure, components similar to those in FIG. 6 is a battery voltage detector that monitors the battery voltage Vb and generates a detection output Sd according to the voltage value, and 7 is a buzzer for alarm.

FIG. 2 is a diagram illustrating an example of a display state on the display unit 2. The display example shown in the figure shows a display screen of a portable pH meter. In the figure, 20 is a battery remaining amount display, 21 is a main measurement signal display (pH value), 22 is an auxiliary signal display (temperature), and 23 is a unit display.
The battery remaining amount display 20 changes its display state according to the detection output Sd of the battery voltage detection unit 6.

  FIG. 3 is a diagram showing a segment configuration and various display states in the battery remaining amount display 20. As shown in the figure, the battery remaining amount display 20 is composed of a basic segment 200 and remaining amount segments 201, 202, 203, and the remaining amount of the battery is indicated by the lighting state of the remaining amount segments 201-203.

In the figure, (a) shows the state of full charge, and all the remaining amount segments 201 to 203 are lit.
Here, the battery voltage detection unit 6 has comparison values VH, VL, and Vg,
VH>VL> Vg
VH: voltage level sufficient for operation VL: voltage level that requires charging Vg: operation guarantee voltage (actually a voltage value slightly higher than operation guarantee voltage Vg)
If
Vb> VH
At this time, the display state shown in FIG.

Also, the battery 4 is slightly depleted,
VH> = Vb> VL
Then, as shown in (b), the remaining amount segments 201 and 202 are lit.
Furthermore, the battery 4 is exhausted,
VL> = Vb> Vg
Then, as shown in (c), only the remaining amount segment 201 is lit. In this state, the device cannot be used for a long time, and the battery 4 needs to be charged.

Battery 4 is further depleted,
Vg> = Vb
Then, as shown in (d), all the remaining segments 201 to 203 are turned off, and the basic segment 200 is blinked to notify that the battery is dead. Further, the buzzer 7 is driven as necessary. Further, after this blinking display, the device is shut down.
In a portable measuring instrument (pH meter) to which the present invention is applied, when the device is shut down, a backup operation for saving the current use state and the processing contents being executed to the nonvolatile memory 3 is not performed. Not done.

Further, the monitoring of the battery voltage Vb in the battery voltage detection unit 6 is not always performed, but is performed at intervals of about once every 128 seconds using a timer (counter) or the like.
That is, since the battery voltage Vb does not decrease rapidly, it is not necessary to constantly monitor the battery voltage Vb, and power consumption is reduced even in such a place.

FIG. 4 is a flowchart showing an operation when executing a defragmentation operation for rearranging data stored in the nonvolatile memory 3. The measurement data sequentially acquired during the measurement is stored in the nonvolatile memory 3, but if the data is deleted later, a defragmentation operation is required to use the limited memory area effectively. Become.
For example, assuming that the storage capacity of the nonvolatile memory 3 is 3 KB, the time required for the defragmentation operation is a maximum of 1 to 2 minutes.
For this reason, if the defragmentation operation is started from the state where the battery 4 is exhausted to the level of the operation guarantee voltage Vg, the battery voltage Vb drops to the operation guarantee voltage Vg during the defragmentation operation, and the device shuts down. It may end up.

  Therefore, as shown in FIG. 4, when the start of the defragmentation operation is instructed (S1), the battery voltage detector 6 compares the battery voltage Vb with a predetermined reference value Vd (S2). The battery voltage detector 6 compares the battery voltage Vb with a predetermined reference value Vd in response to a request from the controller 1.

The reference value Vd is set to a value that is larger than the operation guarantee voltage Vg and that has a margin of a voltage value corresponding to an operation time necessary for executing the defragmentation operation.
Vb> = Vd
In this case, the defragmentation operation is executed (S3),
Vb <Vd
At this time, the defragmentation operation is not performed, and this state is notified by the buzzer 7 and is displayed (S4).

  That is, if the battery voltage Vb is equal to or higher than the reference value Vd at the start of the defragmentation operation, the battery voltage Vb does not drop to the operation guarantee voltage Vg during the execution of the defragmentation operation, and the defragmentation operation is interrupted. It will never be done.

  As described above, when performing the defragmentation operation on the nonvolatile memory 3, the battery voltage Vb of the battery 4 is detected in advance, and the defragmentation operation is performed only when the battery voltage Vb is greater than the predetermined reference value Vd. As a result, even when a process for storing data in the nonvolatile memory 3 for a long time, such as a defragmentation operation, is performed, the battery 4 is consumed during the process and the operation of the device is stopped. Even if the electronic device does not have a backup function against the decrease in the battery voltage Vb, the data being stored is not destroyed.

Here, the normal data storage operation such as measurement data storage also has a short access time to the non-volatile memory 3, and the device does not become inoperable due to running out of battery during the data storage. The confirmation of the battery voltage Vb as described above is not performed.
For example, if the battery voltage Vb drops to the guaranteed operation voltage Vg during data storage, the device is shut down after the end of the data storage operation. The battery voltage Vb does not drop to an inoperable voltage during this period.

  In the above description, the defragmentation operation for rearranging the data stored in the nonvolatile memory 3 is illustrated as an example of the data storage operation for the nonvolatile memory 3, but the magnitude of the battery voltage Vb is confirmed in advance. The data storage operation to be performed is not limited to this, and all processes that store data in the nonvolatile memory 3 for a long time are targeted.

  In the above description, a portable measuring instrument (pH meter) is illustrated as an example of an electronic apparatus to which the present invention is applied. However, the form of the electronic apparatus is not limited to this.

FIG. 1 is a configuration diagram showing an embodiment of an electronic device and a data storage method in the electronic device of the present invention. FIG. 2 is a diagram illustrating an example of a display state on the display unit 2. FIG. 3 is a diagram showing a segment configuration and various display states in the battery remaining amount display 20. FIG. 4 is a flowchart showing an operation when a defragmentation operation for rearranging data stored in the nonvolatile memory 3 is executed. FIG. 5 is a configuration diagram illustrating an example of a conventional electronic device.

Explanation of symbols

1 Control unit (CPU)
2 Display 20 Battery level display 21 Main measurement signal display 22 Auxiliary signal display 23 Unit display 3 Non-volatile memory (EEPROM)
4 Battery 5 Voltage drop detector 6 Battery voltage detector 7 Buzzer

Claims (9)

  In an electronic device that is operated by a battery and has a nonvolatile memory for storing data, the electronic device includes a battery voltage detection unit that compares a battery voltage in the battery with a predetermined reference value, and specific data for the nonvolatile memory. An electronic apparatus characterized by confirming a detection output of the battery voltage detection unit in advance when executing a storage operation.   The electronic device according to claim 1, wherein the battery voltage detection unit compares the battery voltage with a predetermined reference value according to a request.   The electronic device according to claim 1, wherein the specific data storage operation is a defragmentation operation for rearranging data stored in the nonvolatile memory.   The electronic device according to claim 1, wherein the reference value for comparing the battery voltages is set to a value larger than an operation guarantee voltage in the electronic device.   The reference value for comparing the battery voltage is set to a value having a margin of a voltage value corresponding to an operation time necessary for executing the specific data storage operation with respect to an operation guarantee voltage in the electronic device. The electronic device according to claim 4, wherein   In a data storage method that is applied to an electronic device driven by a battery and stores data in a nonvolatile memory, the battery voltage of the battery is detected when a specific data storage operation is performed on the nonvolatile memory. The data storage method in the electronic device is characterized in that the data storage operation is executed only when the battery voltage is greater than a predetermined reference value.   The data storage method in the electronic device according to claim 6, wherein the specific data storage operation is a defragmentation operation for rearranging data stored in the nonvolatile memory.   8. The data storage method in the electronic device according to claim 6, wherein the reference value for comparing the battery voltages is set to a value larger than an operation guarantee voltage in the electronic device. The reference value for comparing the battery voltage is set to a value having a margin of a voltage value corresponding to an operation time necessary for executing the specific data storage operation with respect to an operation guarantee voltage in the electronic device. The data storage method in the electronic device according to claim 8, wherein:

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