JPH0535357A - Semiconductor memory device - Google Patents

Abstract

PURPOSE:To shorten time from the turn-on of a power source to the setting of an operation enable state at the semiconductor memory device. CONSTITUTION:When the power source of the semiconductor memory device is turned on, a main control part 1 starts restoring data from a magnetic disk device 4 for saving data to a data storage part 3, data turning to the operation enable state are restored for the unit of a track, and the completion of restorage is stored in a control memory 2. On the other hand, a command from a host device is waited at the main control part 1 during the restorage and executed at the interval of the restorage. The main control part 1 investigates information in the relevant track of the control memory 2, when the information is restored, the data storage part 3 is accessed and when it is not restored, the magnetic disk device 4 for saving data is accessed. Afterwards, the main control part 1 stops restore control and starts normal operations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor memory device,
In particular, the present invention relates to a semiconductor memory device in which the startup time at power-on is shortened.

[0002]

2. Description of the Related Art Conventionally, since a semiconductor memory device of this type uses a volatile memory, it can be operated by a higher-level device after all data has been restored from a magnetic disk device for saving data when the power is turned on. It was in a state.

[0003]

The above-mentioned conventional semiconductor memory device has a drawback that it takes time to start up because the host device cannot access it for a certain time after power-on.

[0004]

A semiconductor memory device according to the present invention controls a data memory unit including a data memory unit composed of a plurality of volatile memory IC memories and a command from a host device. In a semiconductor memory device including a main control unit, a control memory that stores control information, and a data saving magnetic disk device that saves the data contents of the data memory unit, the semiconductor memory device is powered on. Then, the main control unit starts restoring data from the magnetic disk device for data saving to the data storage unit to make it operable to a higher-level device, and the main control unit restores data in track units. The main control unit stores the data access instruction from the host device between restorations by storing that the track area of the control memory has been restored. If not receiving the already restored access to the data storage unit if already restored examined information of the track areas of the control memory, and accesses to the data saving magnetic disk device.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Reference numeral 1 is a main control unit, 2 is a control memory, 3 is a data storage unit, and 4 is a data saving magnetic disk device.

The operation of the present invention will now be described.

First, when the power of the semiconductor memory device is turned on, the main control unit 1 starts restoring data from the data saving magnetic disk device 4 to the data memory unit 3 and puts it in an operable state with respect to the host device. Inform that there is. Restoration of data is performed in track units, and the control memory 2
The fact that the data has been restored is stored in the track area. On the other hand, a data access command from the host device is awaited by the main control unit 1 and is executed between restores.

First, the main control unit 1 checks the information of the track receiving the data access command of the control memory 2, accesses the data storage unit C if the restoration is completed, and accesses the data saving magnetic field if not restored. The disk device 4 is accessed to execute the command. After that, when the data restoration is completed for all the cylinders, the main control unit 1 stops the restoration control and shifts to the normal operation.

[0010]

As described above, the present invention has an effect of improving the operability of the semiconductor memory device by significantly shortening the time from power-on to operation start.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

[Explanation of symbols]

 1 main control unit 2 control memory 3 data storage unit 4 magnetic disk device for data saving

Claims (1)

Claim: What is claimed is: 1. A data storage unit comprising an IC memory, which is a plurality of volatile storage elements, and a main control unit for controlling the data storage unit in response to a command from a host device. In a semiconductor memory device comprising a control memory for storing control information and a data saving magnetic disk device for saving the data content of the data memory unit, the main controller when the semiconductor memory device is powered on. Starts restoration of data from the magnetic disk device for data saving to the data storage unit to make it operable to a higher-level device, and the main control unit performs restoration in track units, In the track area, it is stored that the data has been restored, and when the main control unit receives a data access command from the host device during the restoration, If not the already restored access to the data storage unit if already restored examined re information of said track areas,
A semiconductor memory device, characterized in that the semiconductor memory device is configured to access the data saving magnetic disk device.