JP2002182799A - Power supply switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable one device to deal with the specifications of various power supplies. SOLUTION: A selector part 21 for selecting a designated power supply among eight kinds of power supplies is composed of five selectors 22 to 26. A setting part 31 is a register for storing data for designating the five selectors 22 to 26 to select which power supply. It is possible to change voltage to be fed to each part of a circuit from the selector part 21 by changing the data of the setting part 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a power supply switching device for switching a plurality of power supplies.

[0002]

2. Description of the Related Art In a device equipped with a plurality of types of power supplies, there is a case in which a device having the same configuration other than the power supply and different in only the specifications of the power supply is manufactured. In such a case, a power supply is provided commonly to all devices, and a power supply switching circuit that switches which power supply is supplied to the device from a plurality of power supplies is designed in accordance with the power supply specifications of each device. Has been adopted.

[0003]

However, when a power supply switching circuit is designed in accordance with a power supply specification, a device having a certain power supply specification cannot be used as a device having another power supply specification. Need to be managed. For this reason, for example, it is necessary to keep devices having different power supply specifications as inventory so as to be able to respond to various orders from customers, and it becomes necessary to have unnecessary inventory, and inventory management becomes complicated. There was a problem.

In addition, in the conventional method, an apparatus having a different power supply specification cannot be easily changed to an apparatus having another power supply specification. If the device is not in stock, a new device of the power supply specification must be manufactured, and it was not possible to flexibly respond to orders.

An object of the present invention is to be able to cope with various power supply specifications.

[0006]

According to the first aspect of the present invention,
A power supply switching device for a device equipped with a plurality of power supplies, wherein a plurality of selection means for selecting and outputting one or more of the plurality of power supplies, and setting data for specifying a power supply selected by the selection means are provided. Setting means to be set.

According to the present invention, by changing the setting data of the setting means, the selecting means can change which power supply among a plurality of power supplies is selected. Compatible with specifications. In addition, since it is not necessary to manufacture and manage a device that differs only in the type of power supply as another device, manufacturing management and inventory management are simplified.

In the above invention, the setting data of the setting means may be changed from the application side. With this configuration, the power supply specification can be easily changed from the application side after the device is manufactured. Alternatively, it is possible to flexibly cope with a change in the power supply specification due to a change in the application or the like.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Note that this embodiment is an example, and actually differs depending on the system. FIG. 1 is a diagram illustrating a configuration of a power supply and a power supply switching circuit according to an embodiment of the present invention.

This power supply switching circuit is used, for example, as a power supply switching circuit for a display device having a plurality of power supplies for display and a plurality of power supplies for a control circuit. In FIG. 1, a power supply unit 11 has a 1.8V power supply 12, a 2.5V power supply.
Eight types of power supplies are provided: a power supply 13, a 3.3V power supply 14, a 5.0V power supply, a 24V power supply 17, a -9V power supply 18, and a -24V power supply 19. These power supplies are generated from an AC power supply or a DC power supply such as a battery.

The selector section 21 includes five selectors 22 to
26, and each of the selectors 22 to 26
One of the three or two types of power supplies is selected and output to each part of the circuit.

The selector 22 includes a 1.8 V power supply 12 and a 2.V power supply 12.
One of the output voltages of the 5V power supply 13 and the 3.3V power supply 14 is selected and supplied as the power supply voltage of the CPU. The selector 23 has a 1.8V power supply 12, a 2.5V power supply 13, and a 3.3V power supply.
One of the output voltages of the V power supply 14 is selected and supplied as a power supply for peripheral circuits of the CPU.

The selector 24 includes a 2.5V power supply 13 and 3.
One of the output voltages of the 3V power supply 14 is selected and supplied as a memory power supply voltage. The selector 25 selects one of the output voltages of the 3.3V power supply, the 5.0V power supply and the 12V power supply and supplies it as the ROM rewrite voltage.

The selector 26 has a power supply of -9.0 V and a power supply of -24.
One of the output voltages of the V power supply is supplied as a liquid crystal drive voltage. The setting unit (register) 31 includes selectors 22 to 26
Stores setting data for determining which power supply voltage to output, and the selectors 22, 23, 24, 25, and
26, 8-bit data B0 to B7 are stored.

The setting section 31 stores eight bits of data B0 to B7 for controlling the turning on and off of eight kinds of power supplies. The setting of the data to the setting unit 31 may be performed by a dip switch or the like, or a program built in the apparatus may be provided with a function of setting the data to the setting unit 31.

The setting unit 31 further performs a temperature detection unit 32 for detecting the ambient temperature and a control for stopping the power supply when the temperature detected by the temperature detection unit 32 exceeds a predetermined value. A control unit 33 is provided.

When it is determined which power supply to use, a predetermined value is set in bits corresponding to the selectors 22 to 26 of the setting unit 31 so that the voltage supplied to the CPU,
A voltage to be supplied to the peripheral circuit, a voltage to be supplied to the memory, and a voltage to be supplied to the liquid crystal display device can be arbitrarily selected from eight types of power sources and output from the selectors 22 to 26.

Therefore, by changing the setting data of the setting unit 31, a device having a certain power supply specification can be easily changed to a device having another power supply specification. This eliminates the need to perform inventory management and simplifies inventory management.

Next, the case where various DC power sources of the power supply unit 11 are generated from the output voltage of the battery will be described. In an apparatus using a battery as a power supply, the capacity of the battery is reduced, the voltage is reduced, and the voltage that has been supplied to each part of the circuit may not be maintained. In such a case, rather than stopping the operation of the CPU, there is a case where it is desired to operate the apparatus even if the processing capacity of the CPU is reduced.

The following processing is executed by a control program built in the apparatus. After the power is turned on (Fig. 2,
S11) Check the battery voltage and set the current output voltage to C
It is determined whether or not the power continuously supplied to the PU remains in the battery (S12).

When the remaining capacity of the battery is sufficient,
Holding the initial value “0” of the bit B0 of the selector 22,
The selector 22 outputs a voltage that should be originally supplied to the PU,
Perform normal processing.

On the other hand, if it is determined that the capacity of the battery is small and it is difficult to supply the current voltage to the CPU (S12, YES), the process proceeds to step S13 and the setting unit 3
"1" is set to the bit B0 of the 8-bit storage area corresponding to the selector 22 of 1.

For example, when the bit B0 is "0", the selector 22 selects the output voltage of the 5V power supply 15 and
If the output voltage of the 3.3 V power supply 14 is designed to be selected when 0 is “1”, the bit B0 corresponding to the selector 22 of the setting unit 31 is set to “ By changing to “1”, the voltage supplied to the CPU can be reduced, and the operation of the CPU can be maintained even when the battery capacity is low. When the battery is recovered, the bit B0 corresponding to the selector 22 of the setting unit 31
Can be changed to “0” to increase the voltage supplied to the CPU.

FIG. 3 is a flowchart of a process for turning off unnecessary power during standby. First, it is determined whether or not the CPU is in a standby state (FIG. 3, S21). When the CPU is in the standby state, the process proceeds to step S22, and the RAM is shifted to the standby state. Then, "1" is set to the bit B0 of the 8-bit storage area corresponding to the selector 24 of the setting unit 31 (S23).

For example, when the bit B0 of the 8-bit storage area corresponding to the selector 24 is "0", the selector 24
Selects 3.3V power supply 14 or 5.0V power supply 15,
If the design is such that the 2.5 V power supply 13 is selected when the bit B0 is “1”, the voltage supplied to the memory can be switched to the minimum operating voltage and the power consumption can be reduced when shifting to the standby mode. it can.

Next, it is determined whether or not any operation has been performed in the standby state (S24). If an operation has been performed by the user (S24, YES), the process proceeds to step S25, where "0" is set to bit B0 of the 8-bit storage area corresponding to selector 24 of setting section 31. Further, the RAM is returned from the standby mode to the normal read / write mode (S25).

That is, by changing the 8-bit data of the setting unit 31, the voltage supplied to the RAM can be reduced, and the power consumption in the standby mode can be reduced. next,
FIG. 4 is a flowchart of a process for supplying power to the I / O device.

Some kind of I / O at the interface of the device
It is determined whether or not the device is connected (FIG. 4, S3
1). If the I / O device is not connected to the interface unit (S31, NO), the process proceeds to step S32 so that power is not supplied. Specifically, the value of the corresponding storage area of the setting unit 31 is set to a value such that the selector does not output a voltage.

If an I / O device is connected to the interface unit (S31, YES), the flow advances to step S33 to determine how many volts are supplied to the connected I / O device. As a voltage determination method, for example, a voltage information terminal for transmitting voltage information is provided to a connector of an I / O device connected to the interface unit, a register for reading the voltage information terminal is provided on the device side, The voltage to be supplied to the I / O device is recognized based on the value.

When the voltage to be supplied to the I / O device is determined, the flow advances to step S34 to determine whether or not the device is set to the power saving mode. If the power saving mode is set (S34, YES), the process proceeds to step S35, where no voltage is supplied to the I / O device or a low voltage is supplied.

If it is determined in step S34 that the current mode is not the power saving mode (S34, NO), the process proceeds to step S36, and the setting data of the setting unit 31 is supplied to supply the corresponding voltage to the I / O device. To change.

Thereafter, the I / O is again sent to the interface unit.
It is determined whether or not a device is connected (S37). If nothing is connected to the interface unit, the supply of power is stopped (S38).

According to this embodiment, the voltage to be supplied to the I / O device is determined by the voltage information obtained from the voltage information terminal of the interface unit even for the I / O device having the same interface and different power supply specifications. By recognizing and changing the setting data of the setting unit 31 accordingly, it is possible to cope with I / O devices of various power supply specifications.

FIG. 5 is a flowchart of a process for stopping the supply of power based on the ambient temperature. At first,
The temperature detector 32 measures the ambient temperature (FIG. 5, S4
1). It is determined whether or not the detected temperature is outside the usable temperature range of the device (S42). When the ambient temperature is within the normal range, normal processing is continued.

On the other hand, if the ambient temperature is too high and the device is not suitable for use (S42, YES), the control unit 33 stops the power supply from the power supply unit 11 (S43).
Further, the fact that the power supply has been stopped due to the temperature abnormality is notified to the user by an alarm sound, a warning display or the like (S4
4).

According to this embodiment, the supply of power to each part of the circuit can be stopped by changing the setting data of the setting unit 31. Next, FIG. 6 is an explanatory diagram of a case where the application 61 switches the selector.

The application 61 determines whether each of the selectors 22 to
If the user wants to know which voltage is currently selected, the information of the hardware 63, for example, the power supply 11
A command is sent to the firmware 62 requesting reading of information such as what power supply is present in the I / O device and what I / O device is connected. Here, the firmware 62 includes the application 61 and the hardware 63
Software such as a driver that connects

When the firmware 62 receives a command for requesting hardware information from the application 61, the firmware 62 accesses the register and reads the information.
It is determined whether there is any abnormality in the information. If there is no abnormality in the information, the obtained information is notified to the application 61.

The application 61 notifies the firmware 62 of a command instructing a voltage to be supplied from the power supply unit 11 to each circuit unit or the I / O device based on the information.

The firmware 62 determines which power source is to be selected by the selector unit 21 according to a command from the application 61. Alternatively, the setting unit 31 described above
Of the switching control registers of the selectors 22 to 26 are rewritten, and the voltage to be selected by the selector unit 21 is determined. Further, the firmware 62 notifies the application 61 of the result of power supply switching.

According to this embodiment, the application 61 provides information on the hardware 63, for example, information indicating which power supply is selected and output by the selector unit 21, information on the power supply required by each circuit unit. , Information on the power supply of the I / O device, etc., and instruct the firmware 62 to switch the power supply based on the information. Thus, even when the type of power supply required by the hardware change is changed, a control command is sent from the application 61 to the firmware 62, and the firmware 62 switches the power supply. The voltage supplied to each unit, I / O device, etc. can be changed.

In the above-described embodiment, the switching of the selector unit 21 is performed by the 8-bit data of the setting unit 31, but the data configuration of the setting unit 31 is not limited to the embodiment. In addition, the setting unit 31 may be configured by something other than the register. Further, the present invention is not limited to a display device, but can be applied to any device.

[0043]

According to the present invention, by changing the setting data of the setting means, it is possible to change which power supply among a plurality of power supplies is to be selected and output by the selection means.
One type of device can support different power supply specifications. Also, only the type of power supply supplied to the circuit is different, and there is no need to manufacture and manage a device having the same other configuration as a separate device, which simplifies inventory management and the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a power supply and a power supply switching circuit.

FIG. 2 is a flowchart of a setting process for a setting unit 31 for switching a voltage supplied to a CPU.

FIG. 3 is a flowchart of a setting process for a setting unit when a RAM returns from a standby state.

FIG. 4 is a flowchart for controlling a voltage supplied to an I / O device.

FIG. 5 is a flowchart of a process of stopping power supply according to an ambient temperature.

FIG. 6 is an explanatory diagram when a selector is switched from an application.

[Explanation of symbols]

 11 Power Supply Unit 21 Selector 31 Setting Unit 61 Application 62 Firmware 63 Hardware

Claims (5)

[Claims] 1. A power supply switching device for a device equipped with a plurality of power supplies, comprising: a plurality of selection means for selecting and outputting one or more of the plurality of power supplies; A power supply switching device comprising: setting means for setting data for designating a power supply to be selected. 2. The power supply switching device according to claim 1, wherein the setting data of said setting means can be changed from an application side. 3. An interface section to which another device is connected is provided with a voltage information terminal for transmitting voltage information, and the voltage should be supplied to another device connected based on the voltage information transmitted by the voltage information terminal. The power supply switching device according to claim 1, wherein the power supply switching device recognizes a voltage. 4. The selection means is controlled so as to sequentially supply a low voltage to a high voltage to another device connected via the interface unit, and the selection means selects the voltage based on a response from the other device. 4. The power supply switching device according to claim 1, wherein a power supply voltage to be applied is determined. 5. A power supply switching device comprising an application, a power supply unit, and firmware for connecting the power supply unit, wherein the application acquires information related to a power supply required by each circuit unit via the firmware, and adds the acquired information to the acquired information. A power supply switching device, comprising: notifying the firmware of an instruction to specify a voltage to be supplied based on the firmware; and causing the firmware to supply the voltage specified by the instruction of the application from the power supply unit to each circuit unit.