DATA-STORAGE DEVICE AND DATA ERASING METHOD

• US 20150161040A1
• Filed: 09/29/2014
• Published: 06/11/2015
• Est. Priority Date: 12/09/2013
• Status: Active Grant

• Current Assignee: Silicon Motion Incorporated California (Silicon Motion)
• Original Assignee: Silicon Motion Incorporated California (Silicon Motion)
• Inventors: CHUANG, Chia-Hao
• Granted Patent: US 10,475,516 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G11C 16/16 for erasing blocks, e.g. arrays, words, groups

Abstract

The present invention provides a data-storage device. The data-storage device includes a flash memory and a controller. The flash memory includes a plurality of blocks, and each of the blocks includes a plurality of pages. The controller is arranged to receive an erase signal from a host, and enable the flash memory to sequentially execute an erasing process on at least one first block of the blocks in response to the erase signal, wherein a specific page of the first block has been written by a predetermined value and the other pages of the first block in exception to the specific page have been erased after the erasing process executed on the first block is completed.

Claims

1. A data-storage device, comprising:

a flash memory, comprising a plurality of blocks, wherein each of the blocks comprises a plurality of pages; and

a controller, arranged to receive an erase signal from a host, and enable the flash memory to execute an erasing process on at least one first block of the blocks in response to the erase signal, sequentially, wherein a specific page of the first block has been written by a predetermined value and the other pages of the first block in exception to the specific page have been erased after the erasing process executed on the first block is completed.

2. The data-storage device as claimed in claim 1, wherein each of the pages of each of the blocks has a logical address and a physical address, and the data-storage device further comprises at least one mapping table arranged to store the corresponding relationships between the logical addresses and the physical addresses of the pages.

3. The data-storage device as claimed in claim 2, wherein when the erasing process is completed, the logical addresses of each of the pages of the first block are mapping to the physical address of the specific page of the first block in the mapping table.

4. The data-storage device as claimed in claim 1, wherein the erase signal is produced by a hardware switch.

5. The data-storage device as claimed in claim 1, wherein the erase signal is a purge command.

6. The data-storage device as claimed in claim 1, wherein the erase signal is an enhanced erase command.

7. The data-storage device as claimed in claim 1, wherein the predetermined value is arranged to determine whether the erasing process is completed.

8. The data-storage device as claimed in claim 7, wherein the predetermined value is 0x21.

10. The data erasing method as claimed in claim 8, wherein each of the pages of each of the first blocks has a logical address and a physical address, and the data-storage device further comprises at least one mapping table arranged to store the corresponding relationships between the logical addresses and the physical addresses of the pages.

11. The data erasing method as claimed in claim 10, further comprising updating the mapping table to map the logical addresses of each of the pages of the first block to the physical address of the specific page of the first block when the predetermined value is written into the specific page.

12. The data erasing method as claimed in claim 11, further comprising repeating the steps of erasing data of the other blocks, writing the predetermined value and updating the mapping table until all of the blocks of the flash memory are processed by the steps of erasing data of the other blocks, writing the predetermined value and updating the mapping table.

9. A data erasing method, applied to a data-storage device, wherein the data-storage device comprises a flash memory, the flash memory comprises a plurality of blocks, and the data erasing method comprises:

erasing data of a first block of the blocks in response to an erase signal; and

writing a predetermined value in to a specific page of the pages of the first block after all of the pages of the first block have been earsed.

13. The data erasing method as claimed in claim 9, wherein the erase signal is produced by a hardware switch.

14. The data erasing method as claimed in claim 9, wherein the erase signal is a purge command.

15. The data erasing method as claimed in claim 9, wherein the erase signal is an enhanced erase command.

16. The data erasing method as claimed in claim 9, further comprising determining whether the erasing process is completed according to the predetermined value stored in the first block.

17. The data erasing method as claimed in claim 9, wherein the predetermined value is 0x21.