JPH04259989A - Power control method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control method during data backup of a semiconductor memory device.

[0002] In a semiconductor memory device, if the power supply is interrupted due to a power outage or an artificial interruption during operation, the data in the semiconductor memory will be lost, so the data is evacuated (backed up) to nonvolatile storage such as a magnetic disk. There is a need. For this reason, semiconductor memory devices are equipped with an auxiliary power source (battery) in case of such an unexpected power supply stoppage.

0003

2. Description of the Related Art In conventional semiconductor storage devices, when the power supply from the main power supply stops due to a power outage, etc., the power supply is automatically switched to the auxiliary power supply and data backup processing is performed. Power was supplied to the entire device until all data backup processing was completed.

FIG. 4 shows the configuration of a conventional power supply control system for a semiconductor memory device. In the figure, 1 is an input/output control unit that controls data transfer with a host device, 2 is a semiconductor memory unit composed of semiconductor memory elements, and 3 is a semiconductor memory unit that does not lose stored information even when the power is cut off. A non-volatile memory section, 4 a transfer control circuit section that controls data transfer between the semiconductor memory section 2 and the non-volatile memory section 3, 5 a main power supply section that supplies power to the semiconductor memory device, and 7 a main power supply section when the power is cut off. Main power supply section 5
An auxiliary power supply section 81 supplies power when the main power supply section 5 is not operating, and a power supply switching circuit 81 switches between the main power supply section 5 and the auxiliary power supply section 7 .

As shown in the figure, in the conventional power supply control system, when the power is cut off and the main power supply section 5 does not operate,
The main power supply section 5 and the auxiliary power supply section 7 are connected by the power supply switching circuit 81.
However, since the entire device becomes a load on the auxiliary power supply section 7, the power supply capacity of the auxiliary power supply section 7 had to be large.

[0006]

[Problem to be solved by the invention] For this reason, during data backup processing, power is supplied to parts that are not involved in the processing, which requires a large amount of power consumption and requires a large-capacity auxiliary power supply. Moreover, there was a problem in that the battery used as an auxiliary power source was depleted more quickly. In view of these points, it is an object of the present invention to provide a means for reducing power consumption during data backup processing.

[0007]

[Means for Solving the Problems] The above problems are solved by a power supply control system configured as follows. FIG. 1 is a diagram showing the principle of the present invention.

[0008] An input/output control unit 1 that controls data transfer with a host device, a semiconductor memory unit 2, a non-volatile memory unit 3, and a connection between the semiconductor memory unit 2 and the non-volatile memory unit 3 when power is cut off. In a semiconductor storage device having a transfer control circuit section 4 for controlling data saving, a peripheral circuit section 6, and an auxiliary power supply section 7 for supplying power when the power is cut off, there are no unnecessary parts in the transfer control circuit section 4 for the transfer operation. Sequential power cutoff function 9 that issues instructions to sequentially cut off power supply to different circuits
and a power supply control circuit section 8 which controls the power supply to the circuits in the device divided into a plurality of blocks according to instructions from the power supply sequential cutoff function 9. When data is transferred to the auxiliary power supply section 7, the power consumption of the auxiliary power supply section 7 is reduced by controlling the supply of power only to blocks involved in data retention and data transfer.

[0009]

[Operation] The power supply sequential cutoff function 9 issues an instruction to sequentially cut off the power supply to circuits unnecessary for the transfer operation, and in response to this instruction, the power supply control circuit section 8 supplies power to the circuits in the device divided into multiple blocks. Turn off the power supply sequentially.

0010

Embodiment FIG. 2 is a block diagram of an embodiment of the present invention. In the figure, 8 is a power control circuit that controls the power supplied to circuits in the device that are divided into multiple blocks, and 9 is a power control circuit that determines whether the circuit is necessary for data backup and changes the block number of unnecessary circuits. This is a sequential power cutoff circuit that notifies the circuit. Other components having the same reference numerals as those in FIG. 4 are the same.

In the figure, the semiconductor memory section is divided into six blocks and further divided into a total of 10 circuit blocks including an input/output control section, a peripheral circuit section, a transfer control section, and a nonvolatile storage section for control.

When the power supply from the main power supply section 5 stops due to a power outage or the like while the device is in operation, power is supplied from the auxiliary power supply section 7 according to instructions from the power supply sequential cutoff circuit 9 in the transfer control circuit 4, and the data is backed up. Processing begins. Prior to processing, the sequential power cutoff circuit 9 blocks block number 1 of the circuit portion not involved in data backup processing.
and 2 are notified to the power supply control circuit section 8. In response to this signal, the power supply control circuit section 8 stops power supply to the input/output control section 1 and the peripheral circuit section 6 that are not involved in the backup process. Next, the data in the semiconductor memory section 2 is backed up to the nonvolatile storage section 3 by the transfer control circuit section 4. At this time, the data is sequentially transferred to the nonvolatile storage section 3 starting from the first address of block number 3 in the semiconductor memory section 2 . When the data at the final address of block number 3 has been transferred, the sequential power cutoff circuit 9 notifies the power supply control circuit section 8 of the block number 3, which is the number of the block whose data has been backed up. The power supply control circuit unit 8 that receives this signal cuts off the power to the block. The same process is subsequently performed in the order of block numbers 4, 5, etc., and when the power of block number 8 is cut off, the power supply sequential cutoff circuit 9 notifies the power supply control circuit unit 8 of block numbers 9 and 10. In response to this signal, the power supply control circuit section 8 shuts off the power to the nonvolatile storage section 3 (block number 9), the transfer control circuit section 4 (block number BLOCK 10) in this order, and finally the auxiliary power supply section 7 cuts off the power supply to the power supply control circuit section 3 (block number 9). The process is ended by cutting off the power to section 8.

FIG. 3 shows an example of the configuration of the power supply control circuit section 8 shown in FIG. 2. The power supply control circuit section 8 includes a power supply switching circuit 81 that switches between the main power supply section 5 and the auxiliary power supply section 7 , a decoding section 82 that decodes the circuit block number notified from the power supply sequential cutoff circuit 9 , and a decoding result of the decoding section 82 . It consists of a latch section 83 that holds , and a switch section 84 that is turned on and off according to the information of the latch section 83 and whose output power is supplied to each circuit block. The decoding section 82 and latch section 83 in the figure may be constructed directly with hardware, but they can be constructed more inexpensively if they are replaced with a one-chip microcomputer. Further, the switch section 84 is composed of a power transistor or the like.

[0014]

Effects of the Invention As explained above, the present invention provides a semiconductor storage device in which power is supplied to the internal mechanism of the device by dividing it into functional blocks, and when backing up data, the device is not involved in the processing. By controlling the power to be supplied only to the parts that need to be used, it is possible to reduce power consumption during backup processing to the minimum necessary, thereby reducing the battery capacity required for the device and reducing the battery capacity. This has the effect of making it possible to downsize the battery configuration associated with backup, such as by reducing the size of the battery, or by installing small batteries with a capacity commensurate with the divided blocks in parallel.

[Brief explanation of the drawing]

[Figure 1] Principle diagram of the present invention

[Figure 2] Block diagram of an embodiment of the present invention

[Figure 3] Block diagram of power supply control circuit

[Figure 4] Block diagram of conventional power supply control method

[Explanation of symbols]

1 Input/output control section
2 Semiconductor memory section 3 Nonvolatile storage section 4
Transfer control circuit section 5 Main power supply section
6 Peripheral circuit section 7 Auxiliary power supply section
8 Power supply control circuit section 9 Power supply sequential cutoff function

Claims (1)

[Claims] 1. An input/output control unit (1) that controls data transfer with a host device, a semiconductor memory unit (2), a non-volatile memory unit (3), and a semiconductor memory unit (1) that controls data transfer with a host device.
In a semiconductor storage device having a transfer control circuit section (4) that controls data saving from 2) to a nonvolatile storage section (3), and an auxiliary power supply section (7) that supplies power when the power is cut off, the transfer control circuit In section (4), there is a power supply cutoff function (sequential power cutoff function) that issues instructions to sequentially cut off the power supply to circuits unnecessary for the transfer operation.
9) and a power supply control circuit section (8) that controls the power supply to the circuits in the device divided into multiple blocks according to instructions from the power supply shutdown function (9). From the memory section (2) to the non-volatile storage section (
3) When saving data to the auxiliary power supply section (7), the power consumption of the auxiliary power supply section (7) is reduced by controlling the supply of power only to blocks involved in data retention and data transfer. , a power supply control method for semiconductor storage devices.