JP2013115866A - Control device, storage device, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device and a storage device which do not require a long charge time and battery replacement, and which, when the power supply is cut off, can normally terminate access to a nonvolatile storage unit by a power storage unit having small power storage capacity.SOLUTION: A control device and a storage device 1 comprise a first power supply unit 101, a first power storage unit 102, a second power supply unit 105, a second power storage unit 106 including a capacitor, a first switch, a central control unit 109 which accesses a nonvolatile storage unit 107 through the first switch, a third power supply unit 110, a voltage detection unit 103 which outputs the measured value of a first voltage, and a power source control unit 104 which controls the central control unit 109, the first switch 108, and the third power supply unit 110 on the basis of the measured value of the first voltage. Depending on a drop in the measured value of the first voltage, the power source control unit 104 causes access by the central control unit 109 to stop and turns the first switch 108 off, thereby causing power supply by the third power supply unit 110 to stop.

Description

  The present invention relates to a control device that controls a nonvolatile storage unit, a storage device including the control device, and a display device including the storage device.

  Generally, display devices for displaying advertisements, guidance, vehicle operation information, and the like in vehicles such as trains and buses and public places such as stations and bus stops are CPUs, RAMs, nonvolatile memories, Ethernet controllers, It is comprised by devices, such as PLD (Programmable Logic Device) and FPGA (Field Programmable Gate Array). The nonvolatile memory stores data such as an OS (Operating System), driver software, application software, and display content.

  In such a display device, it is necessary to update the display content and software. Therefore, a plurality of storage areas for each of the display content and software are provided in the nonvolatile memory, and a plurality of storage areas are provided during operation. Any one of them is used. When updating the display content or software, write the updated display content or software to an area that is not currently used among multiple storage areas, and use it after the writing is completed normally Switch the storage area.

  When updating the display content and software, the power supply to the display device may suddenly stop (power cut off). In particular, in vehicles such as trains and buses, power supply to devices necessary for vehicle operation is given priority, and power supply to display devices for displaying advertisements, guidance, vehicle operation information, etc. is guaranteed. Often not.

  If the power interruption occurs during data writing to the nonvolatile memory, the data stored in the nonvolatile memory may be destroyed. In addition, when the power interruption occurs while the management information related to the data storage destination is being written to the nonvolatile memory, there is a possibility that access to a wide area in the nonvolatile memory becomes impossible.

  Thus, for example, Patent Document 1 discloses a device that detects power interruption and supplies power to the nonvolatile memory using a secondary battery as a separate power source when data is being written to the nonvolatile memory at the time of power interruption. ing.

  Further, for example, in Patent Document 2, when the power supply voltage becomes lower than a predetermined threshold, the power supply to the nonvolatile memory is stopped, and the power stored in the power storage unit including the capacitor until the power supply is stopped. An apparatus for completing data writing to a non-volatile memory is disclosed.

Japanese Patent Laying-Open No. 2004-272309 (paragraphs 4 to 5 and FIG. 1) Japanese Patent Laying-Open No. 2011-108219 (paragraphs 9 to 11, FIG. 3)

  However, since the device shown in Patent Document 1 uses a secondary battery, it requires a longer charging time than a capacitor, and when the performance of the secondary battery deteriorates due to repeated charging and discharging. Has a problem that the secondary battery needs to be replaced.

  In addition, since the device disclosed in Patent Document 2 uses only the power stored in the power storage unit when the power is shut down to complete data writing to the nonvolatile memory, it is necessary to include a power storage unit having a large power storage capacity. There is a problem that there is.

  Accordingly, an object of the present invention is to provide a control device that does not require a long charging time and battery replacement, and can normally terminate access to a nonvolatile storage unit by a power storage unit with a small storage capacity when the power is shut off, and the control device And a display device including the storage device.

  The control device according to the present invention stores a first power supply unit that supplies power at a first voltage, and a part of the power supplied from the first power supply unit, wherein the first voltage is A first power storage unit that supplies stored power when the voltage decreases, and a first voltage that converts the first voltage into a second voltage and supplies power to the nonvolatile storage unit at the second voltage. A part of the power supplied from the second power supply unit and the second power supply unit is accumulated, and when the second voltage decreases, the accumulated power is supplied to the nonvolatile storage unit A second power storage unit including a capacitor to perform, a first switch, a central control unit accessing the nonvolatile storage unit through the first switch, and converting the first voltage into a third voltage, A third power supply unit that supplies power to the central control unit at the third voltage; and A voltage detection unit that measures a pressure and outputs a measurement value of the first voltage; and the central control unit, the first switch, and the third power based on the measurement value of the first voltage A power control unit that controls the supply unit, and the power control unit stops access by the central control unit and turns off the first switch in response to a decrease in the measured value of the first voltage. The power supply by the third power supply unit is stopped.

  According to another aspect of the present invention, there is provided a storage device including a nonvolatile storage unit and the control device that controls the nonvolatile storage unit.

  The display device according to the present invention includes a display unit that displays video based on video data supplied from a central control unit, the first voltage is converted into a fourth voltage, and the display unit includes the fourth voltage A fourth power supply unit configured to supply power with a voltage; and the storage device, wherein the power supply control unit is configured such that the measured value of the first voltage is smaller than a predetermined third voltage threshold value. The power supply by the display unit by the fourth power supply unit is stopped.

  According to the control device, the storage device, and the display device according to the present invention, long charging time and battery replacement are unnecessary, and when the power is turned off, the access to the nonvolatile storage unit is normally terminated by the power storage unit with a small storage capacity. be able to.

It is a block diagram which shows roughly the structure of the control apparatus which concerns on Embodiment 1 of this invention, and a memory | storage device containing this. FIG. 2 is a block diagram schematically showing a configuration of a nonvolatile storage unit in FIG. 1. (A) And (b) is a figure which shows an example of a structure of the 1st switch of FIG. (A)-(d) is a figure which shows the other example of a structure of a 1st switch. It is a flowchart which shows the process of the power supply control part of FIG. It is explanatory drawing which shows the case where the fall rate of a supply voltage is slow by the process of the power supply control part of FIG. It is explanatory drawing which shows the case where the fall rate of a supply voltage is quick by the process of the power supply control part of FIG. It is a block diagram which shows roughly the structure of the memory | storage device which concerns on Embodiment 2 of this invention. It is a block diagram which shows schematically the structure of the display apparatus which concerns on Embodiment 3 of this invention.

<< 1 >> Embodiment 1
<< 1-1 >> Configuration of Embodiment 1 [Control Device and Storage Device]
In the first embodiment, a part of a display device for displaying advertisements, guidance, vehicle operation information, etc. in a vehicle (public transport) such as a train or a bus, or in a public place such as a station or a bus stop. And a control device constituting a part of the storage device will be described. The control device according to Embodiment 1 is a device that controls the operation of a nonvolatile storage unit (for example, a nonvolatile memory). In the first embodiment, the control device protects the stored contents of the nonvolatile memory inside the device from being damaged even when the power supply voltage is lowered. The control device uses the second power storage unit made of a capacitor as a power source for supplying power to the nonvolatile storage unit when the power is shut off, and can reduce the power storage capacity that the second power storage unit must have.

  FIG. 1 is a block diagram schematically showing a configuration of a control device and a storage device 1 according to Embodiment 1 of the present invention. In FIG. 1, the control device has a configuration in which the nonvolatile storage unit 107 is removed from the storage device 1. The control device controls writing and reading of data with respect to the nonvolatile storage unit 107 and supply and interruption of power to the nonvolatile storage unit 107.

  As illustrated in FIG. 1, the storage device 1 includes a first power supply unit 101, a first power storage unit 102, a voltage detection unit 103, a power supply control unit 104, and a second power supply unit 105. A second power storage unit 106, a nonvolatile storage unit 107, a first switch 108, a central control unit 109, and a third power supply unit 110.

  The first power supply unit 101 converts the voltage of power supplied through the terminal 111 into a predetermined first voltage, and supplies the power with the first voltage. The first power storage unit 102 stores part of the power supplied from the first power supply unit 101. In addition, the first power storage unit 102 supplies the accumulated power when the voltage supplied from the first power supply unit 101 decreases.

Voltage detecting unit 103, a result of measuring the voltage of the power supplied from the first power supply unit 101 first storage unit 102. outputs a voltage measurement v _n. The power supply control unit 104, the voltage from the measured values v _n received from the voltage detecting unit 103 detects a voltage change, in order to control the power, and outputs an interrupt signal I ₀ the first enable signal E _1.

  The second power supply unit 105 converts the voltage of the power supplied from the first power supply unit 101 into a predetermined second voltage, and supplies the power with the second voltage. Second power storage unit 106 stores part of the power supplied from second power supply unit 105. In addition, the second power storage unit 106 supplies the stored power when the voltage of the power supplied through the terminal 111 decreases and, as a result, the voltage supplied from the second power supply unit 105 decreases. To do.

The non-volatile storage unit 107 operates by the power supplied from the second power supply unit 105 and the second power storage unit 106, stores data (data write) input from the central control unit 109, and stored data Is output (data read) to the central control unit 109. The first switch 108 receives a data write signal from the central control unit 109 to the non-volatile storage unit 107 and the non-volatile storage unit 107 to the central control unit 109 based on the first enable signal E ₁ input from the power supply control unit 104. Connect or disconnect the data read signal to.

The third power supply unit 110 converts the voltage of the power supplied from the first power supply unit 101 into a predetermined third voltage, and supplies the power with the third voltage. Further, the third power supply unit 110 starts or stops power supply based on the _first enable signal E1 input from the power supply control unit 104. The central control unit 109 operates with the power supplied from the third power supply unit 110. Further, the central control unit 109 stops or restarts data writing to the nonvolatile storage unit 109 and data reading from the nonvolatile storage unit 109 based on the interrupt signal I ₀ input from the power supply control unit 104.

[First power supply unit 101]
The first power supply unit 101 receives power at a predetermined input voltage via the terminal 111 and supplies power at a predetermined first voltage. For example, when the voltage input from the terminal 111 is 100 [V] and the voltage of the power to be supplied is 12 [V], the first power supply unit 101 converts the voltage from 100 [V] to 12 [V]. To supply power at the converted voltage. The first power supply unit 101 includes, for example, a power supply circuit such as a linear regulator or a switching regulator, or a power supply IC.

[First power storage unit 102]
The first power storage unit 102 stores part of the power supplied from the first power supply unit 101. The first power storage unit 102 supplies the accumulated power when the voltage of the power supplied from the first power supply unit 101 decreases. First power storage unit 102 includes a capacitor. In non-volatile memory control devices installed in public transportation such as trains and buses, the supply power may be cut off suddenly. The electric power stored in the first power storage unit 102 is supplied so as to continue. For example, the voltage of the power supplied by the first power supply unit 101 is 12 [V], the minimum voltage at which the control device can operate is 6 [V], and the maximum value of the supplied current is 3 [A]. If the operation continuation time required when the power is shut off is 20 [ms], the first power storage unit 102
3 [A] × 20 [ms] = 60 [mC]
It is necessary to accumulate the charge. Therefore, the capacitance C ₁ required for the first power storage unit 102 is
C ₁ = 60 [mC] / (12 [V] −6 [V])
= 10 [mF]
It becomes. As a capacitor having such a large capacitance, for example, an electric double layer capacitor can be used.

[Voltage detection unit 103]
Voltage detecting unit 103, the voltage of the power supplied from the first power supply unit 101 is measured, and outputs a voltage measurement v _n at a digital format. The voltage detection unit 103 can be constituted by, for example, an A / D converter or a power supply monitoring IC. Voltage detecting unit 103, a voltage measurement value v _n, for example, it may be periodically measured output at a predetermined period, or even as measured outputs in response to a request from the power control unit 104 good.

[Power control unit 104]
The power supply control unit 104, the voltage from the measured values v _n received from the voltage detecting unit 103 detects a voltage change, and outputs an interrupt signal I ₀ and the first enable signal E ₁ for the power control of the control device. The power supply control unit 104, after the start of the supply of electric power from the terminal 111, when a voltage measured value _{v n} received from the voltage detecting unit 103 is larger than the predetermined voltage threshold _{V TON,} the first enable signal _{E 1,} the first The switch 108 is turned on, and the third power supply unit 110 is instructed to start power supply. Thereby, power supply to the central control unit 109 by the third power supply unit 110 is started, and access from the central control unit 109 to the nonvolatile storage unit 107 via the first switch 108 becomes possible.

Further, the power supply control unit 104, a voltage measurement value v _n received from the voltage detecting unit 103 detects a voltage drop, the interrupt signal I ₀ notifies the voltage drop to the central control unit 109, a nonvolatile memory from the central controller 109 Access to the unit 107 is stopped. Further, the power supply control unit 104, a voltage measurement value v _n received from the voltage detecting unit 103 detects the voltage recovery, the interrupt signal I ₀ notifies the voltage recovery to the central control unit 109, first the central control unit 109 The access to the nonvolatile storage unit 107 is resumed via the switch 108.

The first power supply unit 101 and the first power storage unit 102 supply power during a period until the voltage of the power supplied from the terminal 111 rapidly decreases and the central control unit 109 stops accessing the nonvolatile storage unit 107. ₁ is turned off by the first enable signal E1, the access from the central control unit 109 to the nonvolatile memory unit 107 is blocked in a circuit and the first enable signal By E ₁ , the third power supply unit 110 is instructed to stop power supply, and the power supply to the central control unit 109 is stopped.

At the power supply control unit 104, a write control signal and a read control signal input from the first switch 108 to the nonvolatile storage unit 107 monitors, at the end of the write command and the read command, first the first enable signal E ₁ It is also possible to cut off the access to the nonvolatile storage unit 107 from the central control unit 109 in a circuit by turning off the first switch 108. At this time, access to the nonvolatile storage unit 107 is not blocked in the middle of the write command and read command, so that the command immediately before the access is blocked can be correctly input to the nonvolatile storage unit 107, and an abnormal command input It is possible to avoid the destruction of the stored contents of the nonvolatile storage unit 107.

[Second power supply unit 105]
The second power supply unit 105 converts the voltage of the power supplied from the first power supply unit 101 and the first power storage unit 102 into a predetermined second voltage, and uses the converted second voltage as power. Supply. For example, when the voltage input from the first power supply unit 101 and the first power storage unit 102 is 12 [V] and the second voltage is 3.3 [V], the second power supply unit 105 , Convert the voltage from 12 [V] to 3.3 [V] and output. As the second power supply unit 105, for example, a power supply circuit such as a linear regulator or a switching regulator or a power supply IC can be used.

[Second power storage unit 106]
Second power storage unit 106 stores part of the power supplied from second power supply unit 105. The second power storage unit 106 supplies the stored power when the voltage input from the second power supply unit 105 is reduced. The second power storage unit 106 supplies power to the nonvolatile storage unit 107 until the storage operation in the nonvolatile storage unit 107 is completed when the voltage of the power supplied from the terminal 111 decreases.

The second power storage unit 106 is composed of, for example, a large capacity capacitor. Capacitance C ₂ required in the second storage unit 106, a maximum current consumption of the nonvolatile memory section 107 IM, the maximum time until the storage operation of the internal nonvolatile memory 107 is completed TM, the second Assuming that the voltage supplied from the power supply unit 105 is V ₄ and the minimum voltage at which the nonvolatile storage unit 107 can operate is V _m , the following formula C ₂ = (IM × TM) / (V ₄ −V _m )
Is required. For example, the maximum current consumption IM of the nonvolatile storage unit 107 is 170 [mA], the longest time TM until the storage operation in the nonvolatile storage unit 107 is completed is 0.5 [s], and the second power supply unit 105 When the supplied voltage V ₄ is 3.3 [V] and the minimum voltage V _{m at} which the nonvolatile storage unit 107 can operate is 3.135 [V],
C ₂ = (170 [mA] × 0.5 [s]) / (3.3 [V] −3.135 [V])
≈ 516 [mF]
It becomes. For example, an electric double layer capacitor can be used as a capacitor having a higher capacitance.

[Nonvolatile storage unit 107]
The non-volatile storage unit 107 operates by the power supplied from the second power supply unit 105, stores data (data writing) input from the central control unit 109, and stores stored data to the central control unit 109. Output (data read). The nonvolatile storage unit 107 holds the stored contents even after the power supply is stopped. For example, an SSD (Solid State Drive) can be used as the nonvolatile storage unit 107. The nonvolatile storage unit 107 has a configuration as shown in FIG. 2, for example.

  The nonvolatile storage unit 107 illustrated in FIG. 2 includes a controller 201, a buffer 202, and NAND flash memories 203 and 204. Electric power is supplied to the controller 201, the buffer 202, and the NAND flash memories 203 and 204 through the terminal 204 in FIG. The controller 201 temporarily stores the write data input from the terminal 205 in the buffer 202, and then reads the data from the buffer 202 and writes it in the NAND flash memory 203 or the NAND flash memory 204. When reading data, the controller 201 reads data from the NAND flash memory 203 or the NAND flash memory 204, temporarily stores the data in the buffer 202, reads the data from the buffer 202, and outputs the data from the terminal 205. When the transfer rate of data input / output from the terminal 205 is low, the controller 201 can perform data writing and data reading without storing data in the buffer 202.

  In the nonvolatile storage unit 107 shown in FIG. 2, when the controller 201 writes data to the NAND flash memories 203 and 204, an area to be written is determined and data is written based on storage management information for managing the data storage location. Do. When the controller 201 reads data from the NAND flash memories 203 and 204, the data is read based on the storage management information. Since there is a possibility that a damaged area exists in the NAND flash memories 203 and 204, the controller 201 performs management based on the storage management information so as not to write to the damaged area. Further, the NAND flash memories 203 and 204 have an upper limit of the number of times of writing, and normal writing is impossible beyond that. Therefore, the controller 201 stores the storage management information so that the writing does not concentrate on a specific area. Used to distribute the write destination area. This storage management information is also stored in the NAND flash memories 203 and 204. Therefore, when the storage management information of the NAND flash memories 203 and 204 is being updated, if the power is cut off, the storage management information is destroyed, and the controller 201 writes data to and reads data from the NAND flash memories 203 and 204. Might fall into a situation where it cannot be executed correctly.

[First switch 108]
The first switch 108 receives a data write signal from the central control unit 109 to the non-volatile storage unit 107 and the non-volatile storage unit 107 to the central control unit 109 based on the _first enable signal E ₁ input from the power supply control unit 104. The data read signal is connected or cut off. As the first switch 108, for example, an AND gate of general-purpose logic can be used. The first switch 108 is, for example, FIG. 3 (a), (b) the configuration as shown in, the write control signal and the first logical AND operation or a read control signal of the enable signal E ₁ and a first enable signal the aND operation of E _1, make the connection or blocking.

The first switch 108 monitors the write control signal and read control signal input from the central control unit 109 to the nonvolatile storage unit 107, when instructed to cut off the first enable signal E _1, write command and read After waiting for the end of the command, it is also possible to operate so as to block access from the central control unit 109 to the nonvolatile storage unit 107 in a circuit. In this case, as the first switch 108, for example, a configuration as shown in FIGS. 4A and 4B show examples of circuits (D flip-flops and AND gates) constituting the first switch 108, and FIG. 4C shows inputs D and EN of the D flip-flops. FIG. 4D is a timing diagram showing a relationship with the output Q, and FIG. 4D is a timing diagram showing an example of the operation of the first switch in FIG. Access to the nonvolatile memory unit 107 is not blocked in the middle of the write command and the read command, so that the command immediately before the access is blocked can be correctly input to the nonvolatile memory unit 107, and the nonvolatile memory due to abnormal command input Destruction of the stored contents of the unit 107 can be avoided.

[Central control unit 109]
The central control unit 109 operates with the power supplied from the third power supply unit 110. In addition, the central control unit 109 stops or restarts data writing to the nonvolatile storage unit 109 and data reading from the nonvolatile storage unit 109 according to the interrupt signal I ₀ input from the power supply control unit 104. The central control unit 109 includes, for example, a CPU (Central Processing Unit) and a RAM (Random Access Memory).

[Third power supply unit 110]
The third power supply unit 110 converts the voltage of the power supplied from the first power supply unit 101 and supplies the power at a predetermined third voltage. Further, the third power supply unit 110 starts or stops the supply of power according to the first enable signal E ₁ input from the power supply control unit 104. For example, when the voltage input from the first power supply unit 101 and the first power storage unit 102 is 12 [V] and the third voltage is 1.2 [V], the third power supply unit 110 Voltage conversion from 12 [V] to 1.2 [V] is performed. As the second power supply unit 105, for example, a power supply circuit such as a linear regulator or a switching regulator or a power supply IC can be used.

<< 1-2 >> Operation of the first embodiment

FIG. 5 is a flowchart showing processing of the power supply control unit 104 according to the first embodiment. The power supply control unit 104, a reduction in the case (step S1), the interrupt signal supply voltage by _{I 0} to the central control unit 109 to which the voltage measurement value _{v n} received from the voltage detecting unit 103 is smaller than the first voltage threshold value _{V T1} And the central control unit 109 stops access to the nonvolatile storage unit 107 (step S2).

Next, the power control unit 104 measures the voltage lowering speed _{v d} (step S3). The power supply control unit 104 obtains twice the voltage measurement value _{v n} received from the voltage detecting unit 103 at time intervals _{T 1.} Assuming that the _first voltage measurement value is v ₁ and the second voltage measurement value is v ₂ , the rate of decrease in power supply voltage is
v _d = (v ₁ −v ₂ ) / T ₁
Is obtained. The voltage measurement value v ₁ may be the voltage measurement value when it is detected that the voltage measurement value v ₁ is smaller than the first voltage threshold value V _T1 .

As shown in FIG. 6, when the voltage drop rate v _d is slow, the voltage drop is notified by an interrupt while the voltage supplied from the first power supply unit 101 drops to the lowest operable voltage V _T2 . The central control unit 109 stops access to the nonvolatile storage unit 107. In this way, the maximum value of the voltage drop rate at which access can be stopped is the voltage drop rate threshold value K _T2 , and the power supply control unit 104 notifies the central control unit 109 of the voltage drop by interruption. the time to stop access to the _{T C,} when the first voltage threshold and _{V T1,} the voltage drop rate threshold _{K T2,} for example, approximately _{K T2 = (V T1 -V T2} ) / T C
It can ask for.

When the voltage lowering speed _{v d} is smaller than the voltage lowering speed threshold _{K T2} (slow) or equal (step S4), and the power control unit 104 continues to monitor the voltage measurements _{v n} received from the voltage detecting unit 103, voltage measurement If the value _{v n} is greater than the first voltage threshold _{V T1} (step S6), and the interrupt signal _{I 0} notifies recovery of the power supply voltage to the central control unit 109, the central control unit 109 to the nonvolatile memory 107 Is resumed (step S7).

When the power supply voltage decrease rate v _d is larger (faster) than the voltage decrease rate threshold value K _T2 (step S4), the central control unit 109 normally stops access to the nonvolatile storage unit 107 as shown in FIG. Can not. At this time, the first enable signal E ₁ turns off the first switch 108 to block the access from the central control unit 109 to the nonvolatile storage unit 107 in a circuit and the first enable signal E _1. Thus, the third power supply unit 110 is instructed to stop power supply, and the power supply to the central control unit 109 is stopped (step S5). At this time, after the first switch 108 is turned off, the power supply stop of the third power supply unit 110 may be delayed for a predetermined time so that the third power supply unit 110 stops the power supply. By setting the power storage capacity of the second power storage unit 106 as a capacity necessary for completion of data writing in the nonvolatile storage unit 107, power is supplied to the nonvolatile storage unit 107 until data writing is completed, and the stored contents in the nonvolatile storage unit 107 are stored. Can be avoided. In addition, since the central control unit 109 does not consume power, more power is supplied from the first power supply unit 101 and the first power storage unit 102 to the nonvolatile storage unit 107 via the second power supply unit 105. Supply is possible.

Further, instead of determining the rate of decrease v _d of the power supply voltage as in the above example, the voltage measurement value v _n received from the voltage detecting unit 103 and the second voltage threshold (e.g., in FIG. 7, the voltage V _T1 and V when it becomes smaller than the set) between the _T2, the first enable signal E _1, the first switch 108 turns off, the circuit manner access to the nonvolatile memory 107 from the central controller 109 while blocked by the first enable signal E _1, to the third power supply unit 110 instructs to stop power supply, it is also possible to stop the power supply to the central control unit 109. As a result, the central control unit 109 can be operated until the power supply voltage drops close to the operable minimum voltage V _T2 , and destruction of the stored contents of the nonvolatile storage unit 107 can be avoided.

As the power supply control unit 104, for example, a microcontroller can be used. Thus, the first voltage threshold V _T1 when detecting a decrease in the power supply voltage, the lowest operable voltage V _T2, and the time T _C until the central control unit 109 stops access to the nonvolatile storage unit 107. Then, the voltage drop speed threshold value K _T2 and the second voltage threshold value can be changed by software, for example.

<< 1-3 >> Effects of First Embodiment According to the configuration of the first embodiment as described above, since the first power storage unit 102 is provided, even when the power is shut off, the predetermined value after the power is shut off During this period, the operation of the control device can be continued.

Further, in the power supply control unit 104, from the voltage measurements v _n received from the voltage detector 103 detects a voltage change, in order to perform power control of the control device on the basis of the voltage lowering speed, with a decrease status of the power supply voltage Power control is possible.

When the power supply voltage decrease rate is slow, the interruption signal I ₀ notifies the central control unit 109 of the voltage decrease, stops the access from the central control unit 109 to the nonvolatile storage unit 107, and further recovers the power supply voltage. Is detected, the central control unit 109 is notified of the voltage recovery by the interrupt signal I _0, and the access from the central control unit 109 to the nonvolatile storage unit 107 is resumed. Therefore, before the access to the nonvolatile storage unit 107 is stopped, a log regarding a voltage drop can be left in the nonvolatile storage unit 107, and the operation can be resumed when the voltage is recovered.

Further, when the reduction rate of the power supply voltage is high, the first enable signal E ₁ by turning off the first switch 108, the access from the central control unit 109 to the nonvolatile storage unit 107 together with the blocking circuit to In response to the first enable signal E ₁ , the third power supply unit 110 is instructed to stop the power supply, and the power supply to the central control unit 109 is stopped. Is prioritized, so that it is possible to avoid destruction of the contents stored in the nonvolatile storage unit 107. In addition, since the central control unit 109 does not consume power, more power is supplied from the first power supply unit 101 and the first power storage unit 102 to the nonvolatile storage unit 107 via the second power supply unit 105. Electric power can be supplied.

  Furthermore, by supplying power from the second power supply unit 105 and the second power storage unit 106, it is possible to complete the storage operation inside the nonvolatile storage unit 107 when the power supply voltage is reduced, and the nonvolatile storage unit 107 The destruction of the stored contents can be avoided.

  In addition, the first switch 108 shuts off the write signal or read signal to the nonvolatile storage unit 107 and stops the power supply from the third power supply unit to the central control unit. The accumulated power can extend the time for supplying power from the second power supply unit to the nonvolatile storage unit, and the capacity required for the second power storage unit can be reduced. In addition, since the battery is not used, the charging time for the power storage unit is short, and it is not necessary to replace the battery due to performance deterioration.

  In addition, when an electric double layer capacitor is used as the second power storage unit 106, it is possible to have a capability of supplying power to the nonvolatile storage unit 107 until data writing is completed.

<< 2 >> Embodiment 2
FIG. 8 is a block diagram schematically showing the configuration of the control device and the storage device 2 according to the second embodiment of the present invention. In FIG. 8, the same or corresponding elements as those shown in FIG. The control device and storage device 2 according to the second embodiment is different from the control device and storage device 1 according to the first embodiment in that the second switch 301 and the central control auxiliary unit 302 are provided.

The second switch 301 starts or stops the supply of power input from the second power supply unit 105 and the second power storage unit 106 according to the first enable signal E ₁ input from the power supply control unit 104. .

  The central control auxiliary unit 302 operates with the electric power supplied from the second switch 301 and receives and outputs data input from the terminal 303. In addition, the central control auxiliary unit 302 provides an auxiliary function to the central control unit 109.

  The central control unit 109 performs control processing according to data input from the central control auxiliary unit 302 and data input from the nonvolatile storage unit 107.

Next, the second switch 301 will be described. The second switch 301 starts or stops the supply of power input from the second power supply unit 105 and the second power storage unit 106 according to the first enable signal E ₁ input from the power supply control unit 104. . For example, a field effect transistor can be used as the second switch 301.

  Next, the central control auxiliary unit 302 will be described. The central control auxiliary unit 302 receives and outputs data input from the terminal 303. In addition, the central control auxiliary unit 302 provides an auxiliary function to the central control unit 109. For example, an Ethernet controller, PLD, FPGA, bus bridge IC, Super I / O, AUDIO IC, temperature sensor, illuminance sensor, and LED (Light Emitting Diode) can be used as the central control auxiliary unit 302. Of these, a plurality may be used.

  According to the configuration of the second embodiment as described above, when the voltage of the power input from the terminal 111 decreases, the power stored in the second power storage unit 106 is supplied to the central control auxiliary unit 302. Since the power is supplied only to the nonvolatile storage unit 107, power supply can be continued until the storage operation in the nonvolatile storage unit 107 is completed, and the storage capacity of the second power storage unit 106 can be further reduced.

<< 3 >> Embodiment 3
FIG. 9 is a block diagram schematically showing the configuration of the display device 3 according to Embodiment 3 of the present invention. In FIG. 9, the same or corresponding components as those shown in FIG. The display device 3 according to Embodiment 3 has a configuration in which the storage device 2 described in Embodiment 2 includes a fourth power supply unit 401 and a display unit 402. Note that a display device can be configured by including the fourth power supply unit 401 and the display unit 402 in the storage device 1 illustrated in FIG. 1.

  The fourth power supply unit 401 converts the voltage of the power supplied from the first power supply unit 101 and the first power storage unit 102 into a fourth voltage, and supplies the power with the fourth voltage. Further, the fourth power supply unit 401 starts or stops the supply of power according to the second enable signal input from the power supply control unit 104.

  The central control auxiliary unit 302 receives and outputs video data input from the terminal 303. The central control unit 109 generates and outputs video data based on the video data input from the central control auxiliary unit 302 and the data input from the nonvolatile storage unit 107. The display unit 402 displays a video based on the video data input from the central control unit 109 with the power supplied from the fourth power supply unit 401.

The power supply control unit 104, after the start of the supply of electric power from the terminal 111, when a voltage measured value _{v n} received from the voltage detecting unit 103 is larger than the predetermined voltage threshold _{V TON,} the second enable signal _{E 2,} of the fourth The power supply unit 401 is instructed to start power supply. As a result, power supply to the display unit 402 is started. Further, the power supply control unit 104, when the measured voltage value _{v n} received from the voltage detecting unit 103 is smaller than the voltage threshold _{V TOFF (V TOFF <V TON} ), the fourth power supply unit by the second enable signal _{E 2} Instruct 401 to stop power supply, and stop power supply to the display unit 402. The voltage threshold value V _TOFF is set to a value larger than the first voltage threshold value (V _T1 in FIGS. 6 and 7). Thereby, when the power supply voltage is lowered, the display unit 402 does not consume power, so the nonvolatile storage unit 107, the central control unit 109, and the central control auxiliary unit from the first power supply unit 101 and the first power storage unit 102. More power can be supplied to 302. The power supply control unit 104, if the voltage measured value v _n received from the voltage detecting unit 103 is greater than the voltage threshold V _TON, indicates the start power supply to the fourth power supply unit 401, the power to the display unit 402 Supply.

The fourth power supply unit 401 converts the voltage of the power supplied from the first power supply unit 101 and the first power storage unit 102, and supplies the display unit 402 with the predetermined fourth voltage. . The fourth power supply unit 401 starts or stops the supply of power according to the _second enable signal E2 input from the power supply control unit 104. For example, when the voltage input from the first power supply unit 101 and the first power storage unit 102 is 12 [V] and the fourth voltage is 3.3 [V], the fourth power supply unit 401 is The voltage is converted from 12 [V] to 3.3 [V] and output. As the fourth power supply unit 401, for example, a power supply circuit such as a linear regulator or a switching regulator, or a power supply IC can be used.

  The display unit 402 operates with the power supplied from the fourth power supply unit 401 and displays a video based on the video data input from the central control unit 109. As the display unit 402, for example, an LCD panel including an LCD module and a backlight unit can be used.

  According to the configuration of the third embodiment as described above, the display unit 402 does not consume power when the power supply voltage is reduced. Therefore, the first power supply unit 101 and the first power storage unit 102 are connected to the nonvolatile storage unit 107. More power can be supplied to the central control unit 109 and the central control auxiliary unit 302.

  1, 2 storage devices, 3 display devices, 101 first power supply unit, 102 first power storage unit, 103 voltage detection unit, 104 power supply control unit, 105 second power supply unit, 106 second power storage unit, 107 nonvolatile memory unit, 108 first switch, 109 central control unit, 110 third power supply unit, 111 terminal, 201 controller, 202 buffer, 203 NAND flash memory, 204 NAND flash memory, 301 second switch, 302 Central control auxiliary unit, 303 terminal, 401 fourth power supply unit, 402 display unit.

Claims (16)

A first power supply for supplying power at a first voltage;
A first power storage unit that stores a part of the power supplied from the first power supply unit and supplies the stored power when the first voltage decreases;
A second power supply unit that converts the first voltage into a second voltage and supplies power to the nonvolatile storage unit at the second voltage;
A second capacitor that stores a part of the power supplied from the second power supply unit and includes a capacitor that supplies the stored power to the nonvolatile memory unit when the second voltage drops; A power storage unit;
A first switch;
A central control unit accessing the non-volatile storage unit through the first switch;
A third power supply unit that converts the first voltage into a third voltage and supplies power to the central control unit at the third voltage;
A voltage detector that measures the first voltage and outputs a measured value of the first voltage;
A power control unit that controls the central control unit, the first switch, and the third power supply unit based on the measured value of the first voltage;
The power supply control unit stops access by the central control unit in response to a decrease in the measured value of the first voltage, turns off the first switch, and supplies power by the third power supply unit. A control device characterized by stopping.   The power supply control unit prohibits access to the nonvolatile storage unit by the central control unit when a measured value of the first voltage becomes smaller than a predetermined first voltage threshold value. The control apparatus according to 1.   When the measured value of the first voltage becomes larger than the first voltage threshold after the measured value of the first voltage becomes smaller than the first voltage threshold, the non-volatile storage unit by the central control unit The control device according to claim 2, wherein access to the device is permitted.   The power supply control unit turns off the first switch when the rate of decrease in the measured value of the first voltage is greater than a predetermined voltage decrease rate threshold value, and switches from the central control unit to the nonvolatile storage unit. The control device according to any one of claims 1 to 3, wherein access is blocked.   The power supply control unit stops power supply to the central control unit by the third power supply unit when the rate of decrease in the measured value of the first voltage is greater than a predetermined voltage decrease rate threshold. The control device according to claim 4.   When the measured value of the first voltage is smaller than a predetermined second voltage threshold that is lower than the first voltage threshold, the power supply control unit turns off the first switch and performs the central control. 4. The control device according to claim 1, wherein access to the nonvolatile storage unit from a unit is blocked. 5.   When the measured value of the first voltage is smaller than a predetermined second voltage threshold value that is lower than the first voltage threshold value, the power supply control unit is configured to perform the central control unit by the third power supply unit. The control device according to claim 6, wherein power supply to the power supply is stopped.   The access blocking by the first switch is executed when a write command from the central control unit to the nonvolatile memory unit is completed. The control device described in 1.   6. The power supply to the central control unit by the third power supply unit is stopped when a write command from the central control unit to the nonvolatile storage unit is completed. Or the control apparatus of 7.   The power supply to the central control unit by the third power supply unit is stopped after the first switch is turned off. The control device according to item.   The control device according to any one of claims 1 to 10, wherein the second power storage unit is an electric double layer capacitor.   The control device according to claim 1, wherein the power control unit is a microcontroller. A central control auxiliary unit for supplying the received data to the central control unit;
A second switch for switching to an on state in which power is supplied from the second power supply unit and the second power storage unit to the central control auxiliary unit or an off state in which the power is not supplied;
Further comprising
The power supply control unit turns off the second switch and stops power supply to the central control auxiliary unit when the measured value of the first voltage becomes smaller than the second voltage threshold value. 8. The control device according to claim 6 or 7, wherein: The nonvolatile storage means;
14. A storage device comprising: the control device according to claim 1 that controls the nonvolatile storage unit. A display unit for displaying video based on video data supplied from the central control unit;
A fourth power supply unit that converts the first voltage into a fourth voltage and supplies power to the display unit at the fourth voltage;
A storage device according to claim 14,
The power supply control unit stops power supply by the display unit by the fourth power supply unit when the measured value of the first voltage becomes smaller than a predetermined third voltage threshold value. Display device.   The display device according to claim 15, wherein the third voltage threshold is greater than or equal to the first voltage threshold.

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