MEMORY CONTROLLER, NONVOLATILE MEMORY DEVICE,ACCESS DEVICE, AND NONVOLATILE MEMORY SYSTEM

• US 20100017557A1
• Filed: 07/26/2007
• Published: 01/21/2010
• Est. Priority Date: 07/26/2006
• Status: Abandoned Application

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Maeda, Takuji, Honda, Toshiyuki, Nakanishi, Masahiro
• Application Number:
  US12/374,678
• Publication Number:
  US 20100017557A1
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/1416 by checking the object accessibility, e.g. type of access defined by the memory independently of subject rights G06F12/1458 takes precedence
• CPC Class Codes: G06F 2212/7204 Capacity control, e.g. partitioning, end-of-life degradation
• CPC Class Codes: G06F 2212/7206 Reconfiguration of flash memory system
• CPC Class Codes: G11C 29/76 using address translation or modifications
• CPC Class Codes: G11C 29/82 for EEPROMs

Abstract

A nonvolatile memory device reads and writes file data according to a file ID designated by an access device. The nonvolatile memory device includes a capacity parameter decision part 260 which generates a capacitance parameter related to a usable capacity of a nonvolatile memory 210. Even if a defective region of the nonvolatile memory is gradually increased as the use is continued, a capacity parameter decision part 161 reduces a normal region in accordance with increase of the defective region. The capacity parameter notification part notifies the reduced capacity parameter to the access device. Based on the notified capacity parameter, the access device manages the total size of all the files to be read and written.

Claims

1. A memory controller which is connected to a nonvolatile memory, comprising:

a read and write controller for writing data and reading data from said nonvolatile memory in accordance with a file ID designated by an outside;

a capacity parameter determination part for determining a usable capacity parameter of said nonvolatile memory depending on a degree of defects of said nonvolatile memory; and

a capacity parameter notification part for notifying the outside of said capacity parameter.

2. The memory controller according to claim 1, wherein

said capacity parameter determination part reduces the capacity parameter every time the bad block number of said nonvolatile memory increases.

3. The memory controller according to claim 1, wherein

said capacity parameter determination part reduces the capacity parameter in a stepwise fashion every time the bad block number of said nonvolatile memory increases in stepwise fashion.

4. The memory controller according to claim 1, wherein,

every time a value of said capacity parameter is changed, said capacity parameter notification part notifies the outside of the change.

5. The memory controller according to claim 1, wherein,

when a value of said capacity parameter is changed by a certain amount, said capacity parameter notification part notifies the outside of the change.

6. A nonvolatile memory device which writes data and reads data from said nonvolatile memory in accordance with a file ID designated by an outside, wherein

said nonvolatile memory device includes:

the nonvolatile memory; and

a memory controller for writing and reading data to and from said nonvolatile memory, and

said memory controller includes;

a read and write controller for writing data to said nonvolatile memory and reading data from said nonvolatile memory in accordance with a file ID designated by an outside;

a capacity parameter determination part for determining a usable capacity parameter of said nonvolatile memory depending on a degree of defects of said nonvolatile memory; and

a capacity parameter notification part for notifying the outside of said capacity parameter.

7. The nonvolatile memory device according to claim 6, wherein,

every time a value of said capacity parameter is changed, said capacity parameter notification part notifies the outside of the change.

8. The nonvolatile memory device according to claim 6, wherein,

every time a value of said capacity parameter is changed by a certain amount, said capacity parameter notification part notifies the outside of the change.

9. The nonvolatile memory device according to claim 6, wherein

said nonvolatile memory is composed of a plurality of physical blocks, and a plurality of said physical block includes:

normal blocks used for reading and writing data; and

a spare block used for a substitute of a bad physical block, and

said capacity parameter determination part reduces the number of the normal blocks of said nonvolatile memory in accordance with increase of the bad physical block.

10. The nonvolatile memory device according to claim 9, wherein

said capacity parameter determination part reduces the capacity parameter every time the bad block number of said nonvolatile memory increases.

11. The nonvolatile memory device according to claim 9, wherein

said capacity parameter determination part reduces the capacity parameter in a stepwise fashion every time the bad block number of said nonvolatile memory increases in a stepwise fashion.

12. A nonvolatile memory system comprising:

an access device; and

a nonvolatile memory device which writes data and reads data from a nonvolatile memory in accordance with a file ID designated by said access device, wherein

said nonvolatile memory device includes;

the nonvolatile memory and a memory controller, and

said memory controller includes;

a capacity parameter determination part for determining a usable capacity parameter of said nonvolatile memory depending on a degree of defects of said nonvolatile memory; and

a capacity parameter notification part for notifying said access device of said capacity parameter.

13. The nonvolatile memory system according to claim 12, wherein,

every time a value of said capacity parameter is changed, said capacity parameter notification part notifies the outside of the change.

14. The nonvolatile memory system according to claim 12, wherein,

every time a value of said capacity parameter is changed by a certain amount, said capacity parameter notification part notifies the outside of the change.

15. The nonvolatile memory system according to claim 12, wherein

said nonvolatile memory is composed of a plurality of physical blocks, and a plurality of said physical block includes:

normal blocks used for reading and writing data; and

a spare block used for a substitute of a bad physical block, and

said capacity parameter determination part reduces the number of the normal blocks of said nonvolatile memory in accordance with increase of the bad physical block.

16. The nonvolatile memory system according to claim 15, wherein

said capacity parameter determination part reduces the capacity parameter every time the bad block number of said nonvolatile memory increases.

17. The nonvolatile memory system according to claim 15, wherein

said capacity parameter determination part reduces the capacity parameter in a stepwise fashion every time the bad block number of said nonvolatile memory increases in a stepwise fashion.

18. An access device which connects with a nonvolatile memory device including a nonvolatile memory, writes data to said nonvolatile memory device and reads data from said nonvolatile memory in accordance with a file ID, wherein

said access device includes:

a receiver for receiving a capacity parameter from said nonvolatile memory device;

an application for reading and writing data from and to said nonvolatile memory device by designating the file ID and for calculating a usable capacity of said nonvolatile memory device based on said capacity parameter; and

a display for displaying information related to the usable capacity of said nonvolatile memory device.

19. The access device according to claim 18, wherein

said application calculates a remaining capacity by subtracting a capacity of data recorded to said nonvolatile memory device from the usable capacity of the nonvolatile memory device calculated based on said capacity parameter, and

said display displays the usable capacity and the remaining capacity of said nonvolatile memory device.

20. The access device according to claim 19, wherein

said application includes:

a total capacity manager for detecting that the calculated remaining capacity is equal to or less than a threshold value, and

said display displays a file erasure outputted from the total capacity manager.