JPS63187355A - Saving system for data of memory device - Google Patents

Abstract

PURPOSE:To shorten a data saving time, by providing a data saving indicator, and saving blocks in which a data saved in a magnetic disk device is different from the data in a semiconductor memory by utilizing a vacant time when access from a host device is interrupted. CONSTITUTION:When the power source of a computer system is disconnected, a power source control circuit 44 sends a power source disconnection indicating signal to a data saving control circuit 42. The data saving control circuit 42 receiving the power source disconnection indicating signal refers to the data saving indicator of a saving indicator part 412, and when all of the data saving indicators are set at OFF states, it sends a power source disconnection permitting signal to the power source control circuit 44 immediately. When the data saving indicator set at an ON state remains, the block data of a data part 411 corresponding to the data saving indicator set at the ON state is saved in the magnetic disk device 43, and after that, the data saving indicator is set at the OFF state, and at a time when all of the data saving indicators are set at the OFF states, the power source disconnection permitting signal is sent to the power source control circuit 44. In such a way, it is possible to shorten the data saving time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for saving data stored in a memory device into a magnetic disk device, The present invention relates to a data saving method that is performed simultaneously with a read process.

[Conventional technology]

In recent years, semiconductor memory elements have made remarkable progress in terms of performance and price, and have come to be used as high-performance external storage devices. However, a drawback of memory devices made of semiconductor memory elements is that the memory is volatile. To this end, a method has been considered in which a magnetic disk device is built into the storage device and the data in the memory is saved to the magnetic disk device.

The first trigger for saving data is the issuance of a save command from software, and the second trigger is a power cut instruction signal from the power control circuit. In this case, it is desirable that the time required to save data from memory to the magnetic disk device is shorter.
As for conventional technology.

A method has been proposed in which if data is not written to memory after it is saved by a save command from software, the data is not saved when the power is turned off (for example, Japanese Patent Laid-Open No. 61-226857 Publication No.)
.

[Problem to be Solved by the Invention] However, in the above-described data saving method, if writing is performed after execution of a save command by software, the time will not be reduced.

There is a drawback that data saving time cannot be shortened by a save command from software.

[Failure to solve the problem]

The data saving method according to the present invention is comprised of a semiconductor memory element, and includes a data part for storing data and a saving indicator part for storing data saving indicators corresponding to blocks, which are units for saving the data, for the number of blocks. With memory.

A magnetic disk device that saves data in memory.

A device consisting of a power supply control circuit that controls power-off, and a data evacuation control circuit that controls evacuation of the data in the memory to a magnetic disk device. After turning on the indicator, checking the evacuation indicator section in an idle state with no access request from a host device, and evacuation of the data of the block corresponding to the data evacuation indicator in the on state to the magnetic disk device, the data evacuation indicator. When the save command is turned off and a save command is received from the host device, or when a power-off instruction is received from the power supply control circuit, the data save indicator that is in the on state among the data save indicators in the save indicator section is turned on. After saving data only for the corresponding block to the magnetic disk device, turn off the data save indicator, and if all the data save indicators are off, do nothing and save to the host device if a save command is received. The present invention is characterized in that a completion signal is transmitted, and when a power-off instruction is received, a power-off permission signal is transmitted to the power supply control circuit.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a data saving method according to an embodiment of the present invention.

The storage device 4 has a data section 411 and a save indicator section 41.
2, a data save control circuit 42, and a magnetic disk device 43.

The power supply control circuit 44 is connected to the host device 2.

From the magnetic disk device 43 to the semiconductor memory 4 when the power is turned on
When data is stored in block 1, after writing data to the data section 411, the data save control circuit 42 turns off the data save indicator of the save indicator section 412 corresponding to the write block.

Therefore, when the restore operation is completed, the evacuation indicator section 4
All 12 data evacuation indicators are in the off state.

After the restore operation is completed, the storage device 4 becomes operable for the host device 2 and accepts write/read commands from the host device 2. However, when a write command from the host device 2 is executed, data is stored in the data section 411. After writing, the data save control circuit 42 sets the data save indicator of the save indicator 412 corresponding to the write block to the on state.

The storage device 4 executes instruction operations in accordance with commands from the host device 2, but there are times when the commands from the host device 2 are interrupted, and this is generally referred to as an idle state.

When the data save control circuit 42 recognizes that the idle state has entered, it sequentially checks the contents of the save indicator section 412 and uses the block data of the data section 411 corresponding to the first detected on-state data save indicator. After writing to the magnetic disk device 43,
Reset the corresponding data evacuation indicator to off state.

When the above-described series of operations is completed, the data save control circuit 42 checks whether there is a command from the host device 2, and if there is no command, repeats the process again.

If there is a command instruction, the instructed operation is executed.

Therefore, priority is always given to processing commands from the host device 2, but access requests from the host device 2 are generally leveled out within a certain period of time, so they are in an on state at any given time. The number of data evacuation indicators is limited to a certain amount.

When a save command is issued from the host device 2, the data evacuation control circuit 42 saves the block data of the data section 411 corresponding to the data evacuation indicator that is in the ON state of the evacuation indicator section 412 to the magnetic disk device 43, and then saves the block data to the magnetic disk device 43. , turn off the data evacuation indicators, and repeat this until all data evacuation indicators are off.

Thereafter, the data save control circuit 42 sends a save completion signal to the host device 2.

When powering down a computer system.

The power supply control circuit 44 sends a power-off instruction signal to the data save control circuit 42. The data save control circuit 42 that has received the power cut instruction signal refers to the data save indicators of the save indicator section 412, and immediately sends a power cut permission signal to the power control circuit 44 if all the data save indicators are off. If a data evacuation indicator that is in the on state remains, block data in the data section 411 corresponding to the data evacuation indicator that is in the on state is evacuated to the magnetic disk device 43, and then the data evacuation indicator is turned off. , when all data save indicators are turned off, a power cut permission signal is sent to the power control circuit 44.

〔Effect of the invention〕

As explained above, the present invention provides a data save indicator corresponding to a block of data in a semiconductor memory,
Blocks in which the data saved in the magnetic disk device and the data in the semiconductor memory are different can be saved by using free time when access from the host device is interrupted.

This has the effect of reducing the data saving time when receiving a save command from a host device and a power cut instruction signal from a power supply control circuit.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. 2... Host device, 4... Storage device, 41... Semiconductor memory 1, 1, 4.11... Data section, 412...
- Evacuation converter section, 42... Data evacuation control circuit, 43... Magnetic disk device, 44... Power supply control circuit.

Claims (1)

[Claims] 1. A memory composed of a semiconductor memory element and consisting of a data section for storing data, and an evacuation indicator section for storing data evacuation indicators corresponding to blocks, which are units for evacuation of the data, for the number of blocks; A storage device consisting of a magnetic disk device that saves data in the memory, a power control circuit that controls turning off the power, and a data save control circuit that controls saving data in the memory to the magnetic disk device. When writing is performed, the data evacuation indicator corresponding to the corresponding block is turned on, and the evacuation indicator section is checked in an idle state with no access request from the host device, and the data of the block corresponding to the data evacuation indicator in the on state is saved. is saved to the magnetic disk device, the data save indicator is turned off, and when a save command is received from the host device and a power cut instruction is received from the power supply control circuit, the data save indicator section is turned off. After saving data to the magnetic disk device only for the block corresponding to the data evacuation indicator that is in the on state among the indicators, turn the data evacuation indicator off, and do nothing if all the data evacuation indicators are off. Immediately, when a save command is received, a save completion signal is sent to the host device,
A data saving method for a storage device, characterized in that when a power-off instruction is received, a power-off permission signal is sent to a power supply control circuit.