JPH0334193A - Semiconductor memory device - 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 [Field of Industrial Application] The present invention relates to a semiconductor memory device incorporating high-speed volatile memory and non-volatile memory, and particularly relates to data transfer from high-speed volatile memory to non-volatile memory.

[Conventional technology]

Semiconductor memory has the advantages of small size, large capacity, and high-speed access, but on the other hand, data disappears when the power is turned off.

It has the disadvantage of being a so-called volatile memory. For this reason, in semiconductor memory devices, for example,
As described in Japanese Patent No. 7, all data in the semiconductor memory is transferred to a non-volatile memory such as a magnetic disk during unloading during a power outage or when the power is cut off due to the end of business.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into consideration the reduction of data saving time, and there is a problem in that as the storage capacity of the semiconductor memory increases, the data saving time increases accordingly. For this reason, even after the end of the job, the operator was tied up until all data had been evacuated.

In addition, during a power outage, batteries are used for evacuation, but because the data evacuation time is long, the discharge time of the battery is also lengthened, leading to the problem that the capacity of the battery increases and the device becomes larger. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor memory device that reduces the saving time when saving data from a high-speed volatile memory such as a semiconductor memory to a non-volatile memory such as a magnetic disk.

[Means to solve the problem]

The above purpose is to provide a semiconductor storage device with a function of storing the address of rewritten data in a high-speed volatile memory. This is achieved by providing a control function for writing to memory.

[Effect]

During normal operation, data is written to high-speed volatile memory in response to a write command from a host device. At this time, this address is stored in the address storage section.

When saving data, the rewritten address can be known by reading this address, so saving only the data at this address can shorten the saving time.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained in detail with reference to FIG.

FIG. 1 shows the semiconductor memory of the present invention! It is a block diagram showing A position.

In FIG. 1, 1 is a semiconductor memory device, 2 is a microprocessor, 3 is a semiconductor memory section of a high-speed volatile memory for storing data, and 4 is a non-volatile memory for data backup. A disk device, 5 is an interface control unit that is a contact point with a host device, 6 is a data transfer control unit, 7 is an address storage unit that stores the address of rewritten data in the semiconductor memory 3, and 8 is a semiconductor memory. An unload control section 9 performs control to write the rewritten portion of the data in the section 3 to the magnetic disk device 4; A load control unit that controls loading, 10 is a power supply control unit, 1↓
1 is a power supply unit that supplies power to the entire semiconductor storage device 1 and includes a battery; 12 is a timing circuit for determining read and write timings. Further, the thin arrow lines indicate the flow of control signals, and the thick lines indicate the flow of data.

First, when the semiconductor storage device (2) is powered on, all data in the magnetic disk device 4 is loaded into the semiconductor memory section 3. During normal operation, the host device reads and writes data from the semiconductor memory section 3. Further, during normal operation, the address of data written in the semiconductor memory section 3 is stored in the address storage section 7.

Next, the unloading operation during normal operation will be explained. When an instruction to turn off the power to the semiconductor storage device 1 is issued, the power control section 10 detects this instruction, interrupts the microprocessor 2, and instructs the microprocessor 2 to start an unload operation. In response to this interrupt, the microprocessor 2 turns on the power to the magnetic disk device 4 supplied from the power supply section 11. The battery is not used during normal unload operation. Next, the microprocessor 2 activates the read circuit of the semiconductor memory section 3 through the unload control section 8, activates the read circuit of the first address of the semiconductor memory section 3, and prepares for reading from the first address.

The microprocessor 2 refers to the address storage section 7 and writes the data at the memory address written in the semiconductor memory 3 to the magnetic disk device 4 according to the data format of the magnetic disk device 4. At this time, the addresses in the semiconductor memory section 3 are read in order from the beginning, and only the data at the rewritten address is transferred to the magnetic disk device 4. When writing is completed, the power to the magnetic disk device 4 is turned off. The microprocessor 2 sends an unload completion signal to the power supply control unit 10, and the power supply control unit 10 reports the power cutoff to the host device and simultaneously cuts off the power to the entire device. The normal unload operation is as described above.

Further, the above operation is performed even during a power outage, but the power supply section 11 operates using a battery.

In the above embodiment, only the data written in the semiconductor memory section 3 is saved to the magnetic disk device during normal unload operation, but if the data save time is not a problem, all data may be transferred. good.

In this way, compared to saving all data to the magnetic disk device 4, only the rewritten data in the semiconductor memory section 3 is transferred, so the transfer time is greatly shortened.

In addition, in the event of a power outage, the data transfer time is shortened, and the battery discharge time is also reduced, so that the battery life can be extended and the device can be made smaller.

〔Effect of the invention〕

According to the present invention, when the power of a semiconductor memory device is turned off, i! Since only the data at the rewritten address in the 6-speed volatile memory is saved to the nonvolatile storage device, the saving time is reduced.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of a semiconductor memory device according to an embodiment of the present invention. 1...Semiconductor storage device, 2...Microprocessor. 3...Semiconductor memory unit 54...Magnetic disk device,
5... Interface control unit, 6... Data transfer control unit, 7... Address storage unit, 8... Unload control unit, 9... Load control unit, 10... Power supply control unit, 11
··Power supply part.

Claims (1)

[Claims] 1. Equipped with a high-speed volatile memory and a non-volatile memory, the data in the non-volatile memory is loaded into the high-speed volatile memory before starting data transfer with the host device, and the high-speed volatile memory is loaded at the end of business or at the time of a power outage. In a semiconductor storage device that transfers data in a volatile memory to the non-volatile memory, an address storage unit that stores an address of rewritten data in the high-speed volatile memory is provided, and the data in the high-speed volatile memory is A semiconductor memory device characterized in that when transferring data to the nonvolatile memory, only data at an address stored in the address storage section is transferred.