Memory and method for data compression and management

• US 8,037,255 B2
• Filed: 11/26/2007
• Issued: 10/11/2011
• Est. Priority Date: 11/24/2006
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Min, Chang-Woo, Jeong, Soon-Yong
• Primary Examiner(s): PEUGH, BRIAN R
• Application Number:
  US11/945,079
• Publication Number:
  US 20080133855A1
• Time in Patent Office: 1,415 Days
• Field of Search: None
• US Class Current: 711/154
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 2212/401 Compressed data

Abstract

A memory and a method for managing data. The memory for compressing and managing data includes a memory unit, wherein the memory unit has a compressed page cache region which includes a plurality of compressed page caches for temporarily storing, compressing and decompressing data; and a compressed page block region which includes a plurality of compressed page blocks for storing compressed data generated through the compression. Since data is stored in the memory after being compressed, it is possible to store much more data. Furthermore, as a great amount of data can be stored at one time, it is possible to minimize a lowering of the data processing speed caused by movement of data between memories.

Claims

1. A method for compressing and managing data in a memory, the method comprising the steps of:

(1) transmitting data, from a secondary memory unit to a primary memory unit;

(2) temporarily storing the data in a Compressed Page Cache Region (CPCR) of the primary memory unit; and

(3) compressing the data by a compression scheme to generate compressed data, and storing the compressed data in a Compressed Page Block Region (CPBR) of the primary memory unit,

wherein the primary memory unit comprises a virtual page table including a plurality of virtual page entry tables including information for compressing and decompressing data.

2. The method as claimed in claim 1, wherein step (3) comprises:

generating the compressed data by compressing the data by the compression scheme;

comparing a size of the compressed data with a size of the data;

generating the data by decompressing the compressed data by a decompression scheme and storing the generated data, when the size of the compressed data exceeds the size of the data; and

storing the compressed data when the size of the compressed data is equal to or less than the size of the data.

3. A method for compressing and managing data in a memory, the method comprising the steps of:

searching a Compressed Page Block Region (CPBR) of a primary memory unit for compressed data corresponding to data, when the data is requested to be loaded; and

decompressing the compressed data by a decompression scheme to generate the data, and temporarily storing the data in a Compressed Page Cache Region (CPCR) of the primary memory unit,

wherein the primary memory unit comprises a virtual page table including a plurality of virtual page entry tables including information for compressing and decompressing data.

4. A method for compressing and managing data in a memory, the method comprising the steps of:

(1) searching for data, in a Compressed Page Cache Region (CPCR) of the primary memory unit, when the data is requested to be unloaded; and

(2) compressing the data by a compression scheme to generate compressed data, and storing the compressed data in a Compressed Page Block Region (CPBR) of the primary memory unit,

wherein the primary memory unit comprises a virtual page table including a plurality of virtual page entry tables including information for compressing and decompressing the data.

5. The method as claimed in claim 4, wherein step (2) comprises:

generating the compressed data by compressing the searched data by the compression scheme;

comparing a size of the compressed data with a size of the data;

generating the data by decompressing the compressed data by a decompression scheme when the size of the compressed data exceeds the size of the data, and storing the generated data; and

storing the compressed data when the size of the compressed data is equal to or less than the size of the data.

6. A method for compressing and managing data in a memory, the method comprising the steps of:

searching, by a controller in a primary memory unit, for compressed data corresponding to data, when the data is output from a secondary memory unit to the primary memory unit; and

decompressing, by the controller, the data in the primary memory unit, by a decompression scheme to generate the data, and outputting the generated data,

wherein the primary memory unit comprises a virtual page table including a plurality of virtual page entry tables including information for compressing and decompressing the data.

7. A memory for compressing and managing data, the memory comprising a memory unit, wherein the memory unit comprises:

a compressed page cache region which includes a plurality of compressed page caches for temporarily storing, compressing and decompressing data;

a compressed page block region which includes a plurality of compressed page blocks for storing compressed data generated through the compression; and

a virtual page table which contains a plurality of virtual page entry tables including information for compressing and decompressing data.

8. The memory as claimed in claim 7, wherein the virtual page entry table comprises information representing a size of a corresponding compressed page, and an index number of a compressed page block which has stored the compressed data.

9. The memory as claimed in claim 8, further comprising a controller, which receives and temporarily stores data in a compressed page cache included in the compressed page cache region when the data is input, generates compressed data by compressing the temporarily stored data by a compression scheme, and stores the compressed data in a compressed page block included in the compressed page block region.

10. The memory as claimed in claim 9, wherein the controller generates compressed data by compressing data by the compression scheme, compares a size of the compressed data and a size of the data;

generates the data by decompressing the compressed data by the decompression scheme and stores the generated data in a compressed page block included in the compressed page block region, when the size of the compressed data is greater than the size of the data; and

stores the compressed data in a compressed page block included in the compressed page block region when the size of the compressed data is equal to or less than the size of the data.

11. The memory as claimed in claim 7, wherein the memory unit further comprises a compressed page block bitmap which includes at least two bits representing whether each compressed page block included in the compressed page block region has been used.

12. The memory as claimed in claim 11, wherein the controller, when data is requested to be loaded, searches the compressed page block included in the compressed page block region for compressed data corresponding to the data, temporarily stores the searched compressed data in a compressed page cache included in the compressed page cache region, decompresses the temporarily stored compressed data by the decompression scheme to generate the data, and temporarily stores the data again.

13. The memory as claimed in claim 12, wherein the controller, when data is requested to be unloaded, searches the compressed page cache included in the compressed page cache region for the data, compresses the searched data by the compression scheme to generate compressed data, and stores the compressed data in the compressed page block included in the compressed page block region.

14. The memory as claimed in claim 13, wherein the controller generates compressed data by compressing data by the compression scheme, compares a size of the compressed data and a size of the data;

generates the data by decompressing the compressed data by the decompression scheme and stores the generated data in a compressed page block included in the compressed page block region, when the size of the compressed data is greater than the size of the data; and

stores the compressed data in a compressed page block included in the compressed page block region when the size of the compressed data is equal to or less than the size of the data.

15. The memory as claimed in claim 11, wherein the controller, when data is requested to be loaded, searches the compressed page block included in the compressed page block region for compressed data corresponding to the data, temporarily stores the searched compressed data in a compressed page cache included in the compressed page cache region, decompresses the temporarily stored compressed data by the decompression scheme to generate the data, and temporarily stores the data again.

16. The memory as claimed in claim 15, wherein the controller, when data is output, searches the compressed page block included in the compressed page block region for compressed data corresponding to the data, temporarily stores the searched compressed data in a compressed page cache included in the compressed page cache region, decompresses the temporarily stored compressed data by the decompression scheme to generate the data, and outputs the generated data.