JPS6371752A - Semiconductor filing device - Google Patents

Abstract

PURPOSE:To minimize the control of access accompanied with data saving processing to improve the throughput of a computer system by providing a data saving mechanism which saves stored contents of a semiconductor memory in every prescribed data unit and an identifying means which identifies already saved contents and unsaved contents out of stored contents of the semiconductor memory in data units. CONSTITUTION:A file controller 5a controls read/write of data from and to the address of a semiconductor memory 1, which a computer 4 accesses, unless data saving is performed. In case of data saving, stored contents of an identify ing means 3 are cleared and a data saving mechanism 2 is controlled to read stored contents of the semiconductor memory 1 in every prescribed unit, and they are stored on an incorporated magnetic disk. If the access (write) is accom panied with the change of stored contents of the semiconductor memory 1, the identifying means 3 is referred, and it is immediately executed if data is already saved. The identifying means 3 is provided with a memory where infor mation indicating whether data is already saved or not is stored as a flag. Thus, the throughput of the computer system is improved.

Description

[Detailed Description of the Invention] [Summary] In a semiconductor file device equipped with a data evacuation mechanism,
By providing a means to distinguish between data that has been saved and data that has not yet been saved, it is possible to
Partial access is now possible while guaranteeing data simultaneity.

[Industrial application field]

The present invention relates to an improvement in a semiconductor file device, particularly a semiconductor file device equipped with a data saving mechanism.

Until now, magnetic disk devices have played a central role in the file devices (external storage devices) used in computer systems, but it is difficult to shorten access time with magnetic disk devices compared to increasing storage capacity. In order to cope with this problem, semiconductor file devices using semiconductor elements have come into practical use.

A semiconductor file device is a device that can be accessed using magnetic disk device commands from a channel through control device emulation.

By replacing it with a magnetic disk device, access time can be significantly reduced.

However, since a semiconductor memory element whose stored contents are volatile when the power is turned off is used, there are devices that have a data saving mechanism using a magnetic disk or the like to cope with this problem.

Therefore, in a semiconductor file device provided with a data saving mechanism, it is required that both shortening of data saving time and guarantee of simultaneity of saved data are satisfied.

[Conventional technology]

FIG. 3 shows a configuration diagram of a conventional example of a semiconductor file device.

1 is a semiconductor memory that uses a semiconductor as a storage element.

Reference numeral 2 denotes a data saving mechanism that saves the contents of the semiconductor memory 1 in predetermined data units according to instructions from the computer 4 as a host device.

Reference numeral 5b denotes a file control device that controls the operation of the semiconductor file device in accordance with instructions given from the computer 4 through the channel 41.

When the need for data evacuation arises at a certain point, the operator issues a data evacuation command to the file control device 5b from the computer 4 through the channel 41.

The file control device 5b controls the data evacuation mechanism 2 based on a command, and the data evacuation mechanism 2 reads the storage contents of the semiconductor memory in predetermined units and stores them on a built-in magnetic disk.

Note that, in order to guarantee the simultaneity of the saved data, the file control device 5b saves the contents of the semiconductor memory! Access to the semiconductor memory j is prohibited until the evacuation of the data is completed.

[Problem that the invention seeks to solve]

In the conventional example, there is a problem in that the computer cannot access the data until all data has been saved after starting data saving.

In other words, the second object of the present invention is to improve the processing capacity of a computer system by making it possible to access the saved data without impairing the simultaneity of the saved data even while the data saving process is in progress. .

[Means for solving problems]

As shown in the principle diagram of FIG. 1, the semiconductor file device according to the present invention can be accessed from a computer through an input/output channel.

Semiconductor memory 1.

and a data saving mechanism 2 that saves the storage contents of the semiconductor memory 1 in predetermined data units.

The semiconductor memory 1 is provided with identification means 3 for identifying the saved contents and the unsaved contents for each data unit among the contents stored in the semiconductor memory 1.

[Effect]

When the computer accesses the semiconductor memory 1 to write data, it first refers to the identification means 3 to check whether the data has been saved, and if the data has been saved, access is allowed, and if the data has not been saved yet, it is allowed to access the semiconductor memory 1. If so, it is preferentially evacuated and then access is allowed, thereby minimizing access restrictions while data is being evacuated.

〔Example〕

FIG. 2 shows a configuration diagram of the embodiment.

The same reference numerals as in FIGS. 1 and 3 refer to the same objects, and their explanation will be omitted.

The file control device 5a is used except when data is being saved.

Similar to the conventional file control device 5b, it controls reading and writing of data to addresses in the semiconductor memory 1 accessed by the computer 4.

When data is to be saved, the information in the identification means 3 is first read and stored in the built-in magnetic disk.

If there is an access to the semiconductor memory l from the computer 4 through the channel 41 during that time.

This is executed if the contents of the semiconductor memory 1 are not changed (reading).

In addition, if the access involves changing the memory contents of the semiconductor memory 1 (writing), first, the identification means 3 is referred to and the 2.
If the data has already been saved, execute this immediately.

For this reason, the identification means 3 is provided with a memory (not shown) that can store, using a flag, whether or not the data has been saved.

If the access involves a change in the storage contents of the semiconductor memory l, and the data has not yet been saved, the file control device 5a reports the status to the channel 41 to the effect that it is retrying, and then saves the data. After instructing the saving mechanism 2 to preferentially save the data, and confirming that the saving has been completed by a signal given from the data saving device t12, it requests the channel 41 to retransmit the previous access.

〔Effect of the invention〕

As described above, in the semiconductor file device according to the present invention, restrictions on access to the semiconductor memory associated with data saving processing can be minimized, and the processing capacity of the computer system can be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the present invention. FIG. 2 is a configuration diagram of the embodiment. FIG. 3 is a configuration diagram of a conventional example. In the figure. 1 is a semiconductor memory, 2 is a data saving mechanism. 3 is an identification means, 4 is a calculator. calculator (channel) Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] A semiconductor memory (1) that can be accessed from a computer through an input/output channel; a data save mechanism (2) that saves the contents of the semiconductor memory (1) in units of predetermined data; and a semiconductor memory (1). 2. A semiconductor file device comprising: identification means (3) for identifying saved and unsaved contents of the storage contents for each data unit.