JPH11144455A - Memory backup control apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set in flexible the optimum backup power feeding period depending on various secondary battery characteristic and memory environment by providing a memory backup control apparatus for variably setting the backup power feeding period from the secondary battery. SOLUTION: Backup power feeding period from the main power supply or chargeable secondary battery 8 can be controlled from a manipulating section 2 for a volatile memory holding the data. A timer circuit 10 for counting the backup power feeding period preset by the manipulating section 2 or backup power feeding period stored in a non-volatile memory 11 and a means for cutting off the backup power feeding from the secondary battery during the counting are provided. Therefore, since the backup power feeding period can be adjusted, even if the backup power feeding period is varied in the memory environment, the secondary battery can be protected from over-discharging condition. Moreover, the volatile memory 11 is also provided with a plurality of memory chips or cards to supply the backup current to each memory unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a memory backup control device and a memory backup control method for controlling a backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data. Things.

[0002]

2. Description of the Related Art Generally, when backing up data in a system requiring a large capacity memory, a volatile memory such as a DRAM (Dynamic RAM) is used as a storage element.

A conventional memory backup control device includes a refresh circuit that lists (rewrites) data for holding data of the DRAM, a selector for switching between system operation and backup in the DRAM refresh, and monitors a system power supply voltage. Power supply voltage monitoring circuit, a backup power supply circuit that obtains the same voltage as the main power supply of the system, a secondary battery that can be charged as a backup power supply, and a charging circuit that charges the secondary battery.

In such a configuration, conventionally, the backup operation is performed as long as the secondary battery has a sufficient capacity, or the battery voltage is monitored by a comparator or the like in order to prevent overdischarge of the secondary battery, and a certain constant voltage is used. If it had dropped to a lower level, the backup power was shut off. For this reason, the backup time of the memory is determined by the capacity of the secondary battery, the current consumption of the volatile memory to be backed up and its peripheral circuits, and varies depending on the state of charge of the secondary battery and the conditions on the load side.

In addition, since a constant voltage charging is generally used in a charging circuit for a secondary battery, the charging time is very long, and the backup guarantee rate from the time when the main power is turned on until the battery is fully charged is low. . Further, in a charge / discharge circuit of a secondary battery, use of secondary batteries having different charge / discharge characteristics was impossible with a common charge / discharge circuit.

[0006]

The conventional memory backup control device is configured as described above.
In addition, the backup time differs due to the difference in battery capacity and the difference in current consumption of the backup memory (difference between manufacturers, presence / absence of an optional memory device, etc.).
The backup time as a set of the battery and the backup memory is usually guaranteed by the backup time at the maximum load. At times other than the maximum load, backup is performed for the guaranteed time or longer. In that case, there is a problem that the life is shortened due to overdischarge of the secondary battery.

Second, in the charging circuit, when the secondary battery is charged at a constant voltage, the time from the start of charging to the full charging after discharging is very long, and backup is guaranteed against interruption of the main power supply due to a power failure during that time. There is a problem that the possibility of being lost is increased.

Third, when a secondary battery having different charge / discharge characteristics is used, a common charge / discharge circuit has problems such as a change in backup power supply time due to a charge current, a charge stop voltage, and a discharge characteristic. However, there was a problem that it became complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to protect a secondary battery by setting a discharge time, to secure a guaranteed time that does not change with the number of backup memory chips, and to shorten the time. Memory backup control device and memory that can increase the backup guarantee rate when the main power supply is stopped for a relatively short time after charging the main power supply and adjust the charging current to use secondary batteries with different capacities and charge / discharge characteristics in the same circuit The purpose is to provide a backup control method.

[0010]

According to a first aspect of the present invention, there is provided a memory backup for controlling backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data. The control device includes a setting unit that variably sets a backup power supply time from the secondary battery.

According to a second aspect of the present invention, there is provided a storage means for storing the backup power supply time set by the setting means, and a backup set by the setting means after the main power supply is turned off. A timer for counting a power supply time or a backup power supply time stored in the storage unit; and a shutoff control unit for interrupting the backup power supply from the secondary battery based on a time-out state of the timer. Things.

According to a third aspect of the present invention, the volatile memory includes a plurality of memory chips or memory cards, and supplies a backup current for each memory chip or memory card.

A fourth invention according to the present invention is a memory backup control device for controlling power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, Voltage detecting means for detecting the voltage of the secondary battery, a table memory for storing a backup power supply time table corresponding to the voltage fluctuation of the secondary battery, and a voltage of the secondary battery detected by the voltage detecting means. Setting means for variably setting the backup power supply time from the secondary battery based on the backup power supply time table stored in the table memory.

According to a fifth aspect of the present invention, the table memory stores a plurality of backup power supply time tables according to the type of the secondary battery.

According to a sixth aspect of the present invention, the power supply time set by the setting means or the power supply time stored in the backup power supply time table is measured after the main power supply is turned off. Timer means for determining whether or not a backup power-off condition determined by a time-out state of the timer means or a voltage state of the secondary battery detected by the voltage detecting means is satisfied, and the determination means And control means for controlling a cut-off state of power supply from the secondary battery when it is determined that the backup power cut-off condition is satisfied.

According to a seventh aspect of the present invention, there is provided a memory backup control device for controlling power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory for retaining data. Charging means for supplying a constant current or a constant voltage to the secondary battery for charging, voltage detecting means for detecting the voltage of the secondary battery, and voltage of the secondary battery detected by the voltage detecting means are set. And charging control means for switching the charging method of the charging means from constant current charging to constant voltage charging when the charging switching voltage is exceeded.

According to an eighth aspect of the present invention, a constant current value during constant current charging can be set to an arbitrary value.

A ninth invention according to the present invention is a memory backup control method for controlling backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, A setting step of setting a backup power supply time from the secondary battery, and a confirmation step of confirming an input state of backup power supply time data to be changed after setting the backup power supply time from the secondary battery, When confirming the input of backup power supply time data to be changed in the confirmation process,
And a rewriting step of rewriting the set backup power supply time data.

A tenth invention according to the present invention is a memory backup control method for controlling backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, A first charging step of starting constant current charging of the secondary battery, a voltage detecting step of detecting a voltage of the secondary battery, and a voltage of the secondary battery detected by the voltage detecting step are set. And a second charging step of starting constant-voltage charging in place of constant-current charging when the charge switching voltage exceeds a predetermined switching voltage.

An eleventh invention according to the present invention is a memory backup control method for controlling backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, A voltage detecting step of detecting a voltage of the secondary battery, and a timing step of timing a set power supply time or a power supply time stored in the backup power supply time table after the main power supply is turned off. A determining step of determining whether or not a backup power-off condition determined by a timing end state in the timing step or a voltage state of the secondary battery detected in the voltage detecting step is satisfied; and When it is determined that the power-off condition is satisfied, the power-supply from the secondary battery is cut off. Than it is.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a block diagram illustrating a configuration of a memory backup control device according to a first embodiment of the present invention. I do.

In FIG. 1, reference numeral 1 denotes a system control unit of the backup control device, and 2 denotes an operation unit for inputting setting data. A main power supply 3 supplies system power from an AC commercial power supply or the like. Reference numeral 4 denotes a power supply voltage monitoring circuit that detects a reduced state and a restored state of the power supply voltage of the system.

Reference numeral 5 denotes a charge control unit for charging the secondary battery when the main power supply is turned on. A booster circuit 6 boosts the voltage of the secondary battery 8 when the main power supply 3 is stopped and outputs a backup power supply. Reference numeral 7 denotes a discharge control unit that controls switching between the main power supply 3 and the backup power supply and discharge of the data backup power supply from the system control unit 1 and the timer circuit 10. Note that the secondary battery 8 is configured to be chargeable and dischargeable. 9 is DRAM
And the like. Reference numeral 10 denotes a timer circuit such as a clock IC.

Reference numeral 11 denotes a non-volatile memory which stores system data such as set values set from the operation unit 2. Note that the nonvolatile memory 11 is configured by a nonvolatile memory medium such as an SRAM, for example. A primary battery 12 supplies power for the timer circuit 10 and the nonvolatile memory 11.

FIG. 2 is a block diagram for explaining a detailed configuration of the discharge control unit 7 shown in FIG. 1, and the same components as those in FIG. 1 are denoted by the same reference numerals.

In the figure, reference numeral 21 denotes a switching unit which selects one of a DC main power supply and a backup power supply according to a power supply switching signal from the system control unit 1. Reference numeral 22 denotes a shutoff circuit that shuts off power to the backup memory. Reference numeral 23 denotes an internal memory which stores the guaranteed time data input from the operation unit 2 or the memory chip number data counted by the system control unit 1.

Reference numeral 24 denotes a comparing unit which receives time data from the timer circuit 10 such as a clock IC, compares the received time data with the guaranteed time data, and outputs a shutoff instruction to the shutoff circuit 22 based on the comparison result.

FIG. 3 is a block diagram for explaining the detailed configuration of the charging control section 5 shown in FIG. 1. The same components as those in FIG. 1 are denoted by the same reference numerals.

In the figure, reference numeral 31 denotes a switching unit, which switches a constant current charging method in accordance with a charging switching signal from the system control unit 1. A constant voltage circuit 32 and a constant current circuit 33 charge the secondary battery 8 with a constant current. An output voltage limiter 34 controls a limit voltage at the time of charging the secondary battery 8.

Hereinafter, a characteristic configuration of the present embodiment will be described with reference to FIG.

In the memory backup control device configured as described above, the volatile memory 9 for holding data
A memory backup control device for controlling backup power supply from a main power supply or a chargeable / dischargeable secondary battery 8, and setting means (variable operation) for setting a backup power supply time from the secondary battery 8 variably. (Depends on part 2)
Therefore, the optimal backup power supply time can be flexibly set according to the characteristics of various secondary batteries and the memory environment.

A storage means (non-volatile memory 11) for storing the backup power supply time set by the setting means, and a backup power supply set by the operation unit 2 after the main power supply is turned off. A timer circuit 10 for measuring the time or the backup power supply time stored in the non-volatile memory 11, and shutoff control means (discharge control) for shutting off the backup power supply from the secondary battery based on the time-out state of the timer circuit 10. Since the backup power supply time can be adjusted, even if the backup power supply time fluctuates in the memory environment, it is possible to prevent the secondary battery from being over-discharged.

Further, since the volatile memory 11 includes a plurality of memory chips or memory cards and supplies a backup current for each of the memory chips or memory cards, it is possible to supply an optimal backup current to a memory use environment. Can be.

A memory backup control device for controlling power supply from a main power supply or a chargeable / dischargeable secondary battery 8 to a volatile memory 9 for holding data, wherein the voltage of the secondary battery is Voltage detection means (power supply voltage monitoring circuit 4) for detection, table memory (nonvolatile memory 11) for storing a backup power supply time table corresponding to the voltage fluctuation of the secondary battery, and detection by the voltage detection means Setting means (system control unit 1) for variably setting the backup power supply time from the secondary battery based on the voltage of the secondary battery and the backup power supply time table stored in the table memory; It is possible to set a guaranteed time that is not affected by the memory environment used while preventing overdischarge from the secondary battery.

Further, since the table memory stores a plurality of backup power supply time tables according to the type of the secondary battery 8, an optimal backup power supply for various secondary batteries having different discharge times is provided. You can set the time.

A timer means (timer circuit 10) for counting the power supply time set by the setting means or the power supply time stored in the backup power supply time table after the main power supply is turned off.
Determining means for determining whether or not a backup power cutoff condition determined by the timing end state of the time measuring means or the voltage state of the secondary battery detected by the voltage detecting means (power supply voltage monitoring circuit 4) is satisfied ( A comparison unit 24);
When the determination unit determines that the backup power supply cutoff condition is satisfied, the control unit includes a control unit (a cutoff circuit 22) that controls a cutoff state of power supply from the secondary battery. Even if the backup power supply environment fluctuates according to the memory usage status, the backup guarantee rate of the data in the volatile memory can be significantly increased.

Further, the volatile memory 9 for holding data
A memory backup control device for controlling power supply from a main power supply 3 or a chargeable / dischargeable secondary battery, wherein a charging means (a charging means for supplying a constant current or a constant voltage to the secondary battery to charge the secondary battery) A control unit 5), voltage detecting means (output voltage limiter 34) for detecting the voltage of the secondary battery,
When the voltage of the secondary battery detected by the voltage detecting means exceeds a set charging switching voltage, the charging method of the charging means is changed from constant current charging (constant current circuit 33) to constant voltage charging (constant voltage circuit). 32), the secondary battery can be charged in a short time with the same circuit configuration even if the secondary batteries have different charge / discharge characteristics.

Further, since the constant current value at the time of constant current charging can be set to an arbitrary value, flexible constant current charging time can be set with respect to the charging characteristics of the secondary battery, and various secondary batteries can be safely used. Can be charged quickly.

Next, according to the flowchart shown in FIG.
The operation of the memory backup time setting procedure will be described.

FIG. 4 is a flowchart showing an example of a first data processing procedure in the memory backup control device according to the present invention. Note that (1) to (7) indicate each step.

First, after the main power supply 3 is energized (1), the guaranteed time data, which is one of the system data stored in the non-volatile memory 11, is read by the system control unit 1 (2). The guaranteed time data is transferred (3). The guaranteed time data is stored in the internal memory 23 of the discharge controller 7 (4).

After the initial settings of the system including the above settings are completed, the system shifts to the standby state (5). Next, it is determined whether or not guarantee time data has been input from the operation unit 2 during system standby (6), and if YES, the input guarantee time data is written to the nonvolatile memory 11 in which system data is stored. (7) After transferring and storing the guaranteed time data in the internal memory 23 of the discharge control unit 7 again, the process returns to step (3).

On the other hand, if it is determined in step (6) that the guaranteed time data has not been input, the process returns to step (5) and shifts to the standby state.

The charging control procedure for the secondary battery 8 for the backup power supply will be described below with reference to the flowchart shown in FIG.

FIG. 5 is a flowchart showing an example of the second data processing procedure in the memory backup control device according to the present invention. Note that (1) to (14) indicate each step.

When the main power supply 3 is energized (1), the charging current (limit current) in the system data stored in the nonvolatile memory 11 and the secondary battery 8 when switching from constant current charging to constant voltage charging. Read the voltage data of (2),
The charge current and the switching voltage data are transferred to the charge control unit 5 (3).

Next, the charging current data and the switching voltage data are stored in an internal memory in the charging control unit 5, or are set to the set current and the setting voltage by the switching unit 31 in the charging control unit 5 (4). Next, after setting the charging current and the switching voltage, the set current charging is started (5).

After the initial setting of the system including the above settings is completed, the system shifts to the standby state (6). Next, during system standby, it is determined whether or not a charging current or switching voltage has been input from the operation unit 2 (7). If it is determined that a charging current or switching voltage has been input from the operation unit 2, Then, the process proceeds to step (14), where the input charging current or switching voltage data is written into the nonvolatile memory 11 in which the system data is stored, the process returns to step (3), and the data is transferred again into the charging control unit 5. ,
Reset.

On the other hand, if it is determined in step (7) that there is no input of the charging current or the switching voltage from the operation unit 2, the constant current charging is continued (8). Then, the charge control unit 5 detects the voltage of the secondary battery 8 and determines whether or not the switching voltage from the set constant current to the constant voltage has been reached (9), and has determined that the switching voltage has been reached. If
Switching to the constant voltage charging flow (10), and then constant voltage charging is continued (11).

On the other hand, if it is determined in step (9) that the switching voltage has not been reached, the process returns to step (8) to continue the constant current charging.

Next, as in the case of the constant current, the standby state is established during the constant voltage charging (12). During the standby, it is determined whether or not the charging current or the switching voltage is input (13). If it returns to step (11), the constant voltage charging is continued, and if YES, the input charging current or switching voltage data is written into the nonvolatile memory 11 storing the system data (14), and then to step (3). Then, the data is transferred again into the charge control unit and reset.

Hereinafter, a memory backup control procedure after the main power supply 3 is stopped will be described with reference to a flowchart shown in FIG.

FIG. 6 is a flowchart showing an example of a third data processing procedure in the memory backup control device according to the present invention. Note that (1) to (11) indicate each step.

First, when the main power supply 3 stops (1), when the power supply voltage monitoring circuit 4 detects a decrease in the power supply voltage (2),
A DC / DC converter inside the booster circuit 6 is turned on by a control line connected to the booster circuit 6 of the secondary battery 8 from the power supply voltage monitoring circuit 4, and the output of the discharge control unit 7 is switched to the backup power supply side, and volatile The backup power is output to the memory 9 (3). Then, when the backup data exists in the volatile memory 9, the volatile memory chip storing the backup data is selected (4), and the backup refresh circuit of the memory is activated or the self-refresh function is provided. Then, the mode shifts to the self-refresh mode (5).

Next, after the backup operation of a volatile memory such as a DRAM is shifted (6), a real-time clock (hereinafter, RTC) IC having a clock function in the timer circuit 10 is provided.
, The time data is transferred to the discharge control unit 7, and the start time is set (7).

The RTC is executed at regular time intervals or successively.
Time data is transferred from the IC (8), and it is determined whether the elapsed time from the start time has reached the set guaranteed time (9). If it is determined that the guaranteed time has been reached, the discharge control unit 7 To shut off the backup power output (10),
The discharge of the secondary battery 8 is stopped (11).

[Second Embodiment] Hereinafter, with reference to the flowchart shown in FIG.
A memory backup control procedure after FF will be described.

FIG. 7 is a flowchart showing an example of the fourth data processing procedure in the memory backup control device according to the present invention. In addition, (1) to (15) indicate each step.

First, after the main power supply 3 is turned on (1), the system controller 1 detects the number of volatile memory chips for backup or the number of volatile memory chips storing backup data (2).

For example, according to the overdischarge stop voltage table of various secondary batteries for the number of DRAM chips as shown in FIG. 8, a discharge stop voltage is selected (3), and the selected voltage data is transferred to the discharge control unit 7. (4).

Next, the discharge stop voltage data is stored in the internal memory 23 of the discharge control section 7 (5). Alternatively, a method of setting the discharge stop voltage by switching a hard switch may be used. Whenever the chip count data changes,
The chip number data is changed, and the discharge stop voltage of the discharge control unit 7 is reset.

Next, after the main power supply is stopped (6), when the power supply voltage monitoring circuit 4 detects a drop in the power supply voltage (7), the control connected to the booster circuit 6 of the secondary battery from the power supply voltage monitoring circuit 4 Turn on DC / DC converter inside booster circuit 6 with line
Then, the output of the discharge control unit 7 is switched to the backup power supply side, and the backup power supply is output to the volatile memory 9 (8).

Next, when backup data is present in the volatile memory 9, a volatile memory chip storing the backup data is selected (9), and a backup refresh circuit for the memory is activated or self-refresh is performed. If it has the function, it shifts to the self-refresh mode (10).

After the transition to the backup operation of the volatile memory such as the DRAM (11), the voltage of the secondary battery 8 is constantly monitored by the discharge controller 7 (12), and it is determined whether the voltage is equal to or lower than the set stop voltage (13). If it is determined that the voltage is equal to or higher than the set voltage, the process returns to step (12), and the voltage of the secondary battery 8 is constantly monitored.

On the other hand, if it is determined in step (13) that the voltage is equal to or lower than the set voltage, the output of the backup power supply is cut off by the discharge controller 7 (14), and the discharge of the secondary battery 8 is stopped (15).

Hereinafter, the characteristic structure of each embodiment will be further described with reference to FIGS.

A memory backup control method for controlling backup power supply from the main power supply 3 or the chargeable / dischargeable secondary battery 8 to the volatile memory holding data configured as described above, A setting step of setting the backup power supply time from the secondary battery 8 (step (4) in FIG. 4), and after setting the backup power supply time from the secondary battery 8, inputting backup power supply time data to be changed When a confirmation step (step (6) in FIG. 4) for confirming the state and an input of backup power supply time data to be changed in the confirmation step are confirmed,
Since there is a rewriting process (step (7) in FIG. 4) for rewriting the set backup power supply time data, the guaranteed time which is not affected by the memory environment to be used can be variably set.

Also, there is provided a memory backup control method for controlling a backup power supply from a main power supply or a chargeable / dischargeable secondary battery 8 to a volatile memory 9 for holding data. A first charging step (step (5) in FIG. 5) for starting the constant current charging, a voltage detecting step (step (9) in FIG. 5) for detecting the voltage of the secondary battery, and the voltage detecting step A second charging step (step (10) in FIG. 5) for starting constant voltage charging instead of constant current charging when the detected voltage of the secondary battery exceeds the set charging switching voltage. Therefore, even if the secondary batteries have different charge / discharge characteristics, the secondary batteries can be charged in a short time with the same circuit configuration.

Further, the volatile memory 9 for holding data
In contrast, a memory backup control method for controlling backup power supply from the main power supply 3 or the chargeable / dischargeable secondary battery 8, comprising a voltage detection step of detecting a voltage of the secondary battery (step (FIG. 7) 12)) and a clocking step of clocking the set power supply time or the power supply time stored in the backup power supply time table after the main power supply is turned off (step (8) in FIG. 6). And a determining step of determining whether or not a backup power-off condition determined by the timing end state in the timing step or the voltage state of the secondary battery detected in the voltage detecting step is satisfied (step (9) in FIG. 6). , FIG.
Step (13)), and a shut-off step of shutting off the power supply from the secondary battery when it is judged by the judging step that the backup power cut-off condition is satisfied (Step (10) in FIG. 6 and Step (10) in FIG. 7). Step (14)), even if the backup power supply environment fluctuates according to the usage environment of the secondary battery or the memory usage status, the backup guarantee rate of the data in the volatile memory can be significantly increased. .

According to each of the above embodiments, the power supply voltage detecting means for detecting the power supply voltage and the chargeable / dischargeable secondary battery are charged while the main power supply is energized, and are charged while the main power supply is stopped. In a memory backup circuit including a circuit for obtaining a backup power supply from a battery, a memory for holding data, and a unit for determining the number of memory units and the number of memory cards,
A means for setting a backup power supply time is provided. The backup time data is input from the operation unit when the main power is turned on, and the time data is transferred to the discharge control unit.

When the power supply voltage monitoring circuit detects a drop in the power supply voltage, it outputs a backup power supply having the same voltage as the main power supply and activates a backup refresh circuit.
Move to memory backup operation.

After moving to the memory backup operation, time data is periodically transferred from the timer circuit unit and compared with the set time data. When it is determined that the set time has been reached, the discharge control unit cuts off the output of the backup power supply to the volatile memory.

Alternatively, the battery voltage of the secondary battery is input from the operation unit instead of the backup time data, and is transferred to the discharge control unit. The discharge controller monitors the battery voltage of the secondary battery, and shuts off the output of the backup power supply when the battery voltage reaches the set voltage. Or the number of volatile memory chips (memory unit,
The memory controller unit is counted by the system control unit, and the secondary battery voltage for shutting off the output of the backup power supply is calculated from the count data or set from the table data. When the main power supply is energized, the switching operation of the booster circuit and the discharging of the secondary battery are stopped, and the operation is switched to the charging circuit. For the current value (limit current) of the charging current to the secondary battery and the switching voltage from constant current charging to constant voltage charging, the setting data input from the operation unit is transferred to the charging circuit, and the limit current and switching voltage are set. To ensure the secondary battery protection by setting the discharge time, to secure the guaranteed time that does not change with the number of backup memory chips, and to charge the battery in a short time after the main power is turned on. By adjusting the charging current, secondary batteries with different capacities and charge / discharge characteristics can be used in the same circuit.

[0074]

As described above, the first embodiment according to the present invention is described.
According to the invention, a memory backup control device that controls supply of backup power from a main power supply or a rechargeable secondary battery to a volatile memory that retains data, wherein the backup from the secondary battery is performed. Since there is a setting means for variably setting the power supply time, the optimal backup power supply time can be flexibly set according to the characteristics of various secondary batteries and the memory environment.

According to the second invention, the storage means for storing the backup power supply time set by the setting means, and the backup power supply set by the setting means after the main power supply is turned off. Since it has a timer means for counting the time or the backup power supply time stored in the storage means, and a cutoff control means for cutting off the backup power supply from the secondary battery based on a time-out state of the clocking means, The backup power supply time can be adjusted, and even if the backup power supply time fluctuates in the memory environment, it is possible to avoid a situation in which the secondary battery is over-discharged.

According to the third aspect, the volatile memory includes a plurality of memory chips or memory cards, and supplies a backup current for each memory chip or memory card. A backup current can be supplied.

According to the fourth invention, there is provided a memory backup control device for controlling power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, Voltage detection means for detecting the voltage of the battery, a table memory for storing a backup power supply time table corresponding to the voltage fluctuation of the secondary battery, and the voltage of the secondary battery detected by the voltage detection means and the table Setting means for variably setting the backup power supply time from the secondary battery based on the backup power supply time table stored in the memory, so that the memory to be used while preventing overdischarge from the secondary battery You can set a guaranteed time that is not affected by the environment.

According to the fifth aspect, the table memory stores a plurality of backup power supply time tables in accordance with the type of the secondary battery. An optimal backup power supply time can be set.

According to the sixth aspect of the invention, after the main power supply is switched to the off state, the clock for measuring the power supply time set by the setting means or the power supply time stored in the backup power supply time table. Means,
Determining means for determining whether a backup power-off condition determined by a time-out state of the time-measuring means or a voltage state of the secondary battery detected by the voltage detecting means is satisfied; and Control means for controlling a cutoff state of power supply from the secondary battery when it is determined that the condition is satisfied, the backup power supply environment fluctuates according to the usage environment of the secondary battery and the memory usage status. However, the backup guarantee rate of the data in the volatile memory can be significantly increased.

According to the seventh aspect of the present invention, there is provided a memory backup control device for controlling power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory for holding data. Charging means for supplying a constant current or a constant voltage to the battery for charging; voltage detecting means for detecting the voltage of the secondary battery; and charging switching in which the voltage of the secondary battery detected by the voltage detecting means is set. A charge control unit that switches the charging method of the charging unit from constant current charging to constant voltage charging when the voltage exceeds the voltage. Can charge the secondary battery.

According to the eighth aspect, the constant current value at the time of constant current charging can be set to an arbitrary value, so that the constant current charging time can be set flexibly with respect to the charging characteristics of the secondary battery.
Various secondary batteries can be quickly charged safely.

According to a ninth aspect of the present invention, there is provided a memory backup control method for controlling a backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data. A setting step of setting a backup power supply time from the secondary battery, a confirmation step of confirming an input state of backup power supply time data to be changed after the setting of the backup power supply time from the secondary battery, and the confirmation step And a rewriting step of rewriting the set backup power supply time data when the input of the backup power supply time data to be changed is confirmed, so that the guaranteed time is not affected by the memory environment used. Can be freely set.

According to the tenth aspect of the present invention, there is provided a memory backup control method for controlling a backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data. A first charging step of starting constant-current charging of the secondary battery, a voltage detecting step of detecting a voltage of the secondary battery, and a charging in which the voltage of the secondary battery detected by the voltage detecting step is set. A second charging step of starting constant-voltage charging instead of constant-current charging when the switching voltage is exceeded. Therefore, even in the case of secondary batteries having different charge / discharge characteristics, the same circuit configuration can be used in a short time. The secondary battery can be charged.

According to the eleventh invention, there is provided a memory backup control method for controlling backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data. A voltage detection step of detecting the voltage of the next battery, and a timekeeping step of timing a set power supply time or a power supply time stored in the backup power supply time table after the main power supply is switched to an off state, A determining step of determining whether or not a backup power-off condition determined by a time-out state by the time-measuring step or a voltage state of the secondary battery detected by the voltage detecting step is satisfied; and When it is determined that the condition is satisfied, the power supply from the secondary battery is cut off. Be varied backup power supply environment in accordance with the use environment or memory usage of the next cell, it is possible to greatly increase the backup guarantee rate of the data in volatile memory.

Therefore, the charging process can be performed on the secondary battery by switching between the constant current charging and the constant voltage charging, and the rapid charging with the conventional charging time greatly shortened is performed safely, and the charging time is relatively short after the main power is turned on. The backup guarantee rate when the main power supply is stopped can be increased in a short time.

Further, since the charging current to be supplied to the secondary battery can be freely adjusted, the capacity and the capacity can be reduced with the same circuit configuration.
A wide range of secondary batteries with different conditions can be used.

Further, since the backup power supply time can be variably set, it is possible to avoid a situation in which the secondary battery is overdischarged, and to secure a backup guarantee time which is not affected by the number of memory chips constituting the volatile memory. And the like.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a memory backup control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a detailed configuration of a discharge control unit illustrated in FIG.

FIG. 3 is a block diagram illustrating a detailed configuration of a charging control unit illustrated in FIG. 1;

FIG. 4 is a flowchart illustrating an example of a first data processing procedure in the memory backup control device according to the present invention.

FIG. 5 is a flowchart illustrating an example of a second data processing procedure in the memory backup control device according to the present invention.

FIG. 6 is a flowchart illustrating an example of a third data processing procedure in the memory backup control device according to the present invention.

FIG. 7 is a flowchart illustrating an example of a fourth data processing procedure in the memory backup control device according to the present invention.

FIG. 8 is a diagram showing an example of an overdischarge stop voltage table in the memory backup control device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 System control part 2 Operation part 3 Main power supply 4 Power supply voltage monitoring circuit 5 Charge control part 6 Boost circuit 7 Discharge control part 8 Secondary battery 9 Volatile memory 10 Timer circuit 11 Nonvolatile memory 12 Primary battery

Claims (11)

[Claims] 1. A memory backup control device for controlling a backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, the backup power supply from the secondary battery A memory backup control device comprising setting means for variably setting a supply time. 2. A storage unit for storing a backup power supply time set by the setting unit; and a backup power supply time set by the setting unit or the storage unit after the main power supply is turned off. Clocking means for clocking the stored backup power supply time; andinterruption control means for interrupting backup power supply from the secondary battery based on a time-out state of the clocking means,
The memory backup control device according to claim 1, further comprising: 3. The memory backup according to claim 1, wherein the volatile memory includes a plurality of memory chips or memory cards, and supplies a backup current for each memory chip or each memory card. Control device. 4. A memory backup control device for controlling power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, wherein a voltage of the secondary battery is detected. Voltage detection means; a table memory for storing a backup power supply time table corresponding to the voltage fluctuation of the secondary battery; a voltage of the secondary battery detected by the voltage detection means and a backup stored in the table memory Setting means for variably setting a backup power supply time from the secondary battery based on a power supply time table. 5. The memory backup control device according to claim 4, wherein said table memory stores a plurality of backup power supply time tables according to the type of secondary battery. 6. A timer means for clocking the power supply time set by the setting means or the power supply time stored in the backup power supply time table after the main power supply is turned off, and the clocking means. A determination unit that determines whether a backup power cutoff condition determined by the time measurement end state or the voltage state of the secondary battery detected by the voltage detection unit is satisfied; and the determination unit satisfies the backup power cutoff condition. 5. The memory backup control device according to claim 4, further comprising: a control unit configured to control a cutoff state of power supply from the secondary battery when the determination is made. 7. A memory backup control device for controlling power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, wherein the secondary battery has a constant current or a constant current. Charging means for supplying and charging a voltage; voltage detecting means for detecting the voltage of the secondary battery; and when the voltage of the secondary battery detected by the voltage detecting means exceeds a set charging switching voltage. A charge control means for switching a charging method of the charging means from constant current charging to constant voltage charging. 8. The memory backup control device according to claim 7, wherein a constant current value during constant current charging can be set to an arbitrary value. 9. A memory backup control method for controlling a backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, wherein the backup power supply from the secondary battery is provided. A setting step for setting a supply time; a confirmation step for confirming an input state of backup power supply time data to be changed after setting the backup power supply time from the secondary battery; and a backup power supply to be changed by the confirmation step. A rewriting process of rewriting the set backup power supply time data when the input of the supply time data is confirmed,
A memory backup control method, comprising: 10. A memory backup control method for controlling a backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, the method comprising: A first charging step for starting current charging; a voltage detecting step for detecting a voltage of the secondary battery; and a case where the voltage of the secondary battery detected by the voltage detecting step exceeds a set charging switching voltage. And a second charging step of starting constant-voltage charging instead of constant-current charging. 11. A memory backup control method for controlling a backup power supply from a main power supply or a chargeable / dischargeable secondary battery to a volatile memory holding data, wherein a voltage of the secondary battery is detected. A voltage detection step of performing the following steps: a timing step of timing a set power supply time or a power supply time stored in the backup power supply time table after the main power supply is turned off; A determination step of determining whether a backup power shutdown condition determined by a state or a voltage state of the secondary battery detected by the voltage detection step is determined, and it is determined that the backup power shutdown condition is satisfied by the determination step. A power supply from the secondary battery. Backup control method.