SOLID STATE DRIVE AND DATA CONTROL METHOD THEREOF

• US 20120054414A1
• Filed: 11/22/2010
• Published: 03/01/2012
• Est. Priority Date: 09/01/2010
• Status: Abandoned Application

• Current Assignee: Lite-On It Corporation (Lite-On Technology Corporation)
• Original Assignee: Lite-On It Corporation (Lite-On Technology Corporation)
• Inventors: Tsai, Song-Feng, Hsu, Jen-Yu, Chen, Ling-Feng
• Application Number:
  US12/951,384
• Publication Number:
  US 20120054414A1
• 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 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 2212/7211 Wear leveling
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles

Abstract

A solid state drive includes a flash memory and a controlling unit. The flash memory includes plural blocks. Each block includes plural pages. The controlling unit is in communication with the flash memory. When data of a specified block are erased or data are written into the specified block, the controlling unit provides a time parameter to the specified block. The controlling unit performs a data loss prevention, a wear leveling operation or a garbage collection according to the time parameter.

Claims

1. A solid state drive, comprising:

a flash memory comprising plural blocks, wherein each block comprises plural pages; and

a controlling unit in communication with the flash memory, wherein when data of a specified block are erased or data are written into the specified block, the controlling unit provides a time parameter to the specified block, wherein the controlling unit performs a data loss prevention, a wear leveling operation or a garbage collection according to the time parameter.

2. The solid state drive according to claim 1, wherein the solid state drive further comprises a real time clock component in communication with the controlling unit for generating a time signal to the controlling unit, so that the time signal is used as the time parameter.

3. The solid state drive according to claim 1, wherein the solid state drive is in communication with a host, wherein when a file is written from the host to the solid state drive, a time signal is retrieved from the writing time of the file to be used as the time parameter.

4. The solid state drive according to claim 1, wherein the solid state drive is in communication with a host according to a communication protocol, wherein a time signal outputted from the host to the controlling unit is used as the time parameter.

5. The solid state drive according to claim 1, wherein a total erase count of all blocks of the flash memory is counted by the controlling unit to be used as the time parameter.

6. The solid state drive according to claim 1, wherein a first time period is calculated according to a current time parameter and a first time parameter of a first block, wherein if the first time period is longer than the preset time period, the data of the first block are written into a second block so as to perform the data loss prevention.

7. The solid state drive according to claim 1, wherein for performing the wear leveling operation on a third block, the controlling unit selects a fourth block having the lowest time parameter from the flash memory, the data of the third block are written into the fourth block or the data of the third block are exchanged with the data of the fourth block.

8. The solid state drive according to claim 1, wherein for performing the garbage collection, the controlling unit selects a fifth block having the lowest time parameter from the flash memory and judges whether the number of valid pages of the fifth block is lower than a threshold value, wherein if the number of valid pages of the fifth block is lower than the threshold value, the data of the valid pages of the fifth block are written into a sixth block.

9. A data control method of a flash memory, the flash memory comprising plural blocks, each block comprising plural pages, the data control method comprising steps of:

providing a time parameter to a specified block when data of the specified block are erased or data are written into the specified block; and

performing a data loss prevention, a wear leveling operation or a garbage collection according to the time parameter.

10. The data control method according to claim 9, wherein the time parameter is a time signal generated by a real time clock component.

11. The data control method according to claim 9, wherein the flash memory is in communication with a host, wherein when a file is written from the host to the flash memory, a time signal is retrieved from the writing time of the file to be used as the time parameter.

12. The data control method according to claim 9, wherein the flash memory is in communication with a host according to a communication protocol, wherein a time signal outputted from the host is used as the time parameter.

13. The data control method according to claim 9, wherein a total erase count of all blocks of the flash memory is counted and used as the time parameter.

14. The data control method according to claim 9, wherein the data loss prevention is performed by steps of:

calculating a first time period according to a current time parameter and a first time parameter of a first block; and

writing the data of the first block into a second block if the first time period is longer than the preset time period.

15. The data control method according to claim 9, wherein the wear leveling operation is performed on a third block by steps of:

selecting a fourth block having the lowest time parameter from the flash memory; and

writing the data of the third block into the fourth block or exchanging the data of the third block with the data of the fourth block.

16. The data control method according to claim 9, wherein the garbage collection is performed by steps:

selecting a fifth block having the lowest time parameter from the flash memory;

judging whether the number of valid pages of the fifth block is lower than a threshold value; and

writing the data of the valid pages of the fifth block into a sixth block if the number of valid pages of the fifth block is lower than the threshold value.