MEMORY DEVICE AND INFORMATION PROCESSING APPARATUS

Abstract

A file management information area of a memory includes a FAT and a replacement information table. In the FAT, chain information on a file is recorded and in the replacement information table, replacement information of a defective area is recorded. In order to read out the file, a file system reads out the FAT and the replacement information table to generate indexes of the file and stores the indexes to an index buffer. In a memory controller, an address part of a read command is sequentially replaced with indexes stored in the index buffer and page-replaced read commands are continuously transferred to the memory.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an information processing apparatus in accordance with a preferred embodiment of the present invention;

FIG. 2 is a view showing a functional hierarchy of the information processing apparatus;

FIG. 3 is a view showing a state where a file is stored in a memory having a defective area;

FIG. 4 is a flowchart showing an operation for reading a file in accordance with the preferred embodiment;

FIG. 5 is a view showing a state where page indexes are stored in a page index buffer;

FIG. 6 is a view showing an image of command replacement; and

FIG. 7 is a view showing a background-art memory in which replacement information is recorded in part of its memory area.

Claims

1. A memory device in which a file is stored, comprising: a first area for storing file management information; anda second area for storing substance data of a file,wherein said second area comprisesa data area for storing substance data of a file, anda replacement area used as an alternative storage area for substance data if said data area has an area which needs to be replaced, andsaid file management information is information read out by a file system which accesses said memory device, andsaid file management information includes correspondence information between said area which needs to be replaced and said replacement area.

2. The memory device according to claim 1, wherein said file management information includes chain information on a file in a case where there is no area that needs to be replaced and correspondence information between said area which needs to be replaced and said replacement area.

3. The memory device according to claim 1, wherein said file management information includes chain information on a file after said area which needs to be replaced is replaced with said replacement area.

4. The memory device according to claim 1, wherein said memory device is a semiconductor memory and said area which needs to be replaced is replaced with said replacement area on a page-by-page basis.

5. The memory device according to claim 1, wherein said area which needs to be replaced includes a defective area in said data area.

6. The memory device according to claim 1, wherein said area which needs to be replaced includes an area in which data to be updated is recorded, andupdate of data is performed by recording updated data in said replacement area.

7. An information processing apparatus for processing information stored in a memory device in which a file is stored, wherein said memory device comprisesa first area for storing file management information, anda second area for storing substance data of a file, andsaid second area comprisesa data area for storing substance data of a file, anda replacement area used as an alternative storage area for substance data if said data area has an area which needs to be replaced, andsaid file management information is information read out by a file system which accesses said memory device, andsaid file management information includes correspondence information between said area which needs to be replaced and said replacement area,said information processing apparatus comprising:a host system for processing information stored in said memory device; anda controller for controlling access to said memory device,wherein said host system includes a file system used for management of information stored in said memory device, andsaid controller comprisesa page index buffer for storing page indexes of a file, which are acquired from said file management information, anda replacement element, receiving a read command for said file from said host system, for sequentially replacing an address part of said read command with page indexes stored in said page index buffer to continuously transfer page-replaced read commands to said memory device.

8. The information processing apparatus according to claim 7, wherein said file management information includes chain information on a file in a case where there is no area that needs to be replaced and correspondence information between said area which needs to be replaced and said replacement area.

9. The information processing apparatus according to claim 7, wherein said file management information includes chain information on a file after said area which needs to be replaced is replaced with said replacement area.

10. The information processing apparatus according to claim 7, wherein said memory device is a semiconductor memory and said area which needs to be replaced is replaced with said replacement area on a page-by-page basis.

11. The information processing apparatus according to claim 7, wherein page indexes of said file stored in said memory device are read out by said file system,the page indexes read out are stored in said page index buffer by software, andsaid replacement element is formed of hardware.

12. The information processing apparatus according to claim 7, wherein said host system includes a DMA controller, anda read command for said file, which is outputted from said host system, is controlled by said DMA controller and page-replaced read commands obtained by sequentially replacing an address part of said read command with page indexes in said replacement element are burst transferred.

13. The information processing apparatus according to claim 12, wherein a discontinuous file stored at discontinuous page addresses due to presence of an area which needs to be replaced is recorded in said memory device,discontinuous page indexes of said discontinuous file are stored in said page index buffer, andsaid replacement element replaces an address part of a read command with discontinuous page indexes and said DMA controller thereby reads out said discontinuous file with one burst transfer.