JPS61202263A - Data memory system - Google Patents

Abstract

PURPOSE:To attain a high-speed access and easy replacement of data and to improve the reliability with the long-time use of a data memory system, by combining a nonvolatile semiconductor memory device which is capable of electrical erasion and writing and a high-speed volatile semiconductor memory device. CONSTITUTION:A nonvolatile semiconductor memory device 11 which is capable of electrical erasion and writing is stored in a cassette case 12 and used as an external memory. The transfer of data is performed with a main system through the device 11 through a high-speed volatile semiconductor memory device 15 to which data are transferred previously. The data stored in the device 15 are transferred and stored in the device 11 immediately before the device 11 stored in the case 12 is removed and preserved or carried.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to data storage systems used, for example, in small computer systems and office office automation equipment, and particularly relates to improving the performance and reliability thereof.
[Technical background of the invention and its problems] In recent years, 3.5-inch floppy disks have been commercialized as external storage devices for small computer systems and the like. The recording medium of this floppy disk is housed in a durable case, making it easy to handle.
There are problems as described below. First of all, since data is accessed by mechanically moving the magnetic head, the access speed is slower than that of semiconductor memory devices.

Second, since the magnetic head is brought into close contact with the recording medium for access, both the recording medium and the magnetic head are subject to severe wear, which poses a problem of reduced reliability during long-term use.

As an external storage device that does not have such drawbacks, there is a read-only ROM cassette that uses a FROM that can be erased by irradiation with ultraviolet light. This ROM cassette is used as a medium for distributing NotWare O in, for example, inexpensive ROM machines. However, while the ROM cassette has a faster access speed than the floppy disk device and is free from wear, it cannot be electrically erased.
It is difficult to update all the data since it is used.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose is to provide an excellent data storage system that allows high-speed access and data updating and that does not deteriorate in reliability even after long-term continuous use.

[Summary of the invention]

That is, in order to achieve the above object, the present invention combines a non-volatile semiconductor memory device that can be electrically erased and written with a high-speed volatile semiconductor memory device for summer use. The non-volatile semiconductor memory device is stored in a cassette case and used as an external storage device, and can be used as an external storage device between the main system and this system. Data is transferred to and from the volatile semiconductor memory device to which data has been transferred from the nonvolatile semiconductor memory device. Immediately before the nonvolatile semiconductor memory device housed in the cassette case is removed and stored or transported, the data stored in the volatile semiconductor memory device is transferred to and stored in the nonvolatile semiconductor memory device.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Figure 1 is a block diagram showing the schematic configuration of the system. Set to several hundred kilobytes or more, which is sufficient for the device.

The board equipped with the above nonvolatile semiconductor memory I711 is
It is housed in a strong case (cassette case) 12, and can be stored and transported by removing it from the case 12fc main body. The nonvolatile semiconductor memory 11 is connected to a main system (not shown) via an interface device 13, and is also connected to a volatile semiconductor memory 15 and a control device 1 via an internal bus 14.
Connected to 6. A dynamic or static type memory device is used as the volatile semiconductor memory 15, and its capacity is set to be approximately the same as that of the nonvolatile semiconductor memory 11. The interface device 13 interposed between the cable line 17 from the main system and the internal nozzle 14 electrically connects the two when the main system accesses the system, and facilitates data transfer within the system. Sometimes it plays the role of separating the main system from the main system. Then, the control device 16
Data transfer and control of the interface device 13 are performed via the internal bus 14.

In the above configuration, when the cassette case 12 is attached, data is transferred from the nonvolatile semiconductor memory 11 to the volatile semiconductor memory 15 and stored therein, and when the cassette case 212 is taken out, the data is transferred to the volatile semiconductor memory 15 immediately before being ejected. Data is transferred from semiconductor memory 15 to nonvolatile semiconductor memory 11 and stored. For data access from the main system, the volatile semiconductor memory 15
use. That is, the designated data is read from the volatile semiconductor memory 15 and transferred to the main system, and then transferred to the designated storage area of the volatile semiconductor memory device 15. At this time, if the data stored in the volatile semiconductor memory device 15 is updated, only this updated data is written to the nonvolatile semiconductor memory device 11 when the cassette case 12 is removed. The transfer speed can be increased.

With this configuration, data can be accessed from the main system at a higher speed than when using a floppy disk. This is because when using a floppy disk, it takes several milliseconds to move between magnetic tracks, but when using semiconductor memory, this waiting time is no longer necessary, and the main memory Access speed comparable to the access time of the device can be obtained.

Still magnetic, like a floppy disk.

Since the card and recording medium are not used in close contact with each other,
There is no mechanical wear even during long-term use, improving reliability.

Furthermore, unlike ROM cases, the present invention can also be applied to systems that require updating of data.

FIG. 2 shows an external perspective view of the system shown in FIG. 1 above. 17 is a main body, and this main body 27 has the above-mentioned first
DRA equipped with non-volatile semiconductor memory 11 in the figure
A control door 19 equipped with a control device 16 and an interface device 13 is housed therein.

Reference numeral 20 indicates a cassette holder plate, and the cassette holder plate 20 is provided with a two-way connector 21a.

The connector 21b of the cassette case 12 inserted from the cassette insertion port 22 is inserted into the spring type connector 21m, and the nonvolatile semiconductor memory 11, DRAM, N
- The board 18 and the control board 19 are electrically connected. Note that 22 indicates heat radiation holes 23, 23. The upper cover 24 is a switch (not shown) which serves both to start the power supply of the system and to fix the connectors 21a and 21b. When using this system by incorporating it into the main system, remove the main body case and power supply.

FIG. 3 shows a more detailed example of the configuration of FIG. 1. In FIG. 1, an Fg2P 0M25 is used for the nonvolatile semiconductor memory 11, and a dynamic type memory 26 is used for the volatile semiconductor memory 15. FB above
The storage capacities of the FROM 25 and the dynamic memory 26 are each set to, for example, 1 Mbyte.The control device 16 includes an 8-bit CPU 27, a working memory IJ 28, and a DMA controller 29.The working memory 28 includes: The DMA controller 29 uses the R and OM that store the control program, and a small capacity M for the work area.
251:> This is for transferring 1 Mbyte of data stored in the dynamic memory 26 at high speed. The I10 port 30 is for an interface with the outside, and the address extension circuit 31 is for an 8-bit CPU.
21 to access a 1M byte address space.

Although the CPU 27'i is 8 bits here, if a high-performance CPU such as a 16-bit CPU is used, a larger storage capacity can be used as the FE2PROM 25 and the dynamic memory 26.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to obtain an excellent data storage system that allows high-speed access and whose reliability does not deteriorate even when used continuously for a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a schematic configuration of a data storage system according to an embodiment of the present invention, Fig. 2 is an external perspective view of the data storage system shown in Fig. 1 above, and Fig. 3 is Fig. 1 shown in Fig. 1 above. FIG. 2 is a block diagram for explaining a more detailed configuration of the data storage system shown in FIG. DESCRIPTION OF SYMBOLS 11... Nonvolatile semiconductor memory, I2... Cassette case, 13... Interface device, 14...
Internal bus, 15... Volatile semiconductor memory, 16...
Control device. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Noi > Sysuwo 4

Claims (2)

[Claims] (1) A nonvolatile semiconductor memory device that can electrically erase and write data, an interface device provided between the nonvolatile semiconductor memory device and an external main system, and an internal bus for the nonvolatile semiconductor memory device. the nonvolatile semiconductor memory device, the control device controlling the nonvolatile semiconductor memory device, the interface device, and the volatile semiconductor memory device to transfer data; is detachably installed in the system, and immediately after the nonvolatile semiconductor memory device is installed in the system, the data stored in the nonvolatile semiconductor memory device is transferred to the volatile semiconductor memory device, and the volatile semiconductor memory device is transferred to the volatile semiconductor memory device. Data is read and written between the memory device and the external main system via the interface device, and the data stored in the volatile semiconductor memory device is transferred to the nonvolatile semiconductor memory device immediately before removing the nonvolatile semiconductor memory device. A data storage system characterized by transcribing and storing data. (2) The data storage system according to claim 1, wherein only updated data is written when data stored in the volatile semiconductor memory device is transferred to the nonvolatile semiconductor memory device.