Memory controller including a hardware compression and decompression engine for managing system memory and graphical operations

• US 8,711,164 B2
• Filed: 05/07/2012
• Issued: 04/29/2014
• Est. Priority Date: 11/16/1994
• Status: Expired due to Fees

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Inventors: Dye, Thomas A.
• Primary Examiner(s): KIM, HONG CHONG
• Application Number:
  US13/465,838
• Publication Number:
  US 20120212498A1
• Time in Patent Office: 722 Days
• Field of Search: 345/555, 711/170, 711/154, 711/159, 711/160, 710/68, 709/247, 708/203, 382/244
• US Class Current: 345/555
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems
• CPC Class Codes: G06F 2212/401 Compressed data
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/125 wherein one of the images is motion video
• CPC Class Codes: G09G 2360/121 using a cache memory
• CPC Class Codes: G09G 2360/125 using unified memory architecture [UMA]
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/14 Display of multiple viewports
• CPC Class Codes: G09G 5/363 Graphics controllers
• CPC Class Codes: G09G 5/39 Control of the bit-mapped memory

Abstract

An integrated memory controller (IMC) may sit on the main CPU bus or a high speed system peripheral bus and couple to system memory. The IMC may use a lossless data compression and decompression scheme for improved performance. The IMC may also include microcode for specific decompression of particular data formats such as digital video and digital audio. Compressed data may be decompressed in the IMC and stored into system memory or saved in the system memory in compressed format. Internal memory mapping may allow for format definition spaces which may define the format of the data and the data type to be read or written. Software overrides may be placed in applications software in systems that desire to control data decompression at the software application level.

Claims

1. A method, comprising:

receiving, at a memory controller, a request from a processor for a first block of data for use in data processing operations;

identifying a second block of data stored in memory as uncompressed data, wherein said identifying is performed by the memory controller in response to determining that the first block of data is stored in the memory as compressed data;

freeing a portion of the memory by compressing, using the memory controller, the second block of data and storing the compressed second block of data in the memory;

decompressing, using the memory controller, the first block of data and storing the decompressed first block of data in the memory; and

performing the data processing operations using the decompressed first block of data.

2. The method of claim 1, wherein said identifying is based on a determined likelihood that the second block of data will be accessed.

3. The method of claim 1, wherein said performing the data operations includes:

mapping a first area of the memory to first information related to a first graphic display window of a display; and

mapping a second area of the memory to second information related to a second graphic display window of the display.

4. The method of claim 3, wherein said storing the decompressed first block of data includes:

storing the first information in the first area of memory; and

storing the second information in the second area of memory.

5. The method of claim 1, further comprising:

identifying the decompressed first block of data as most recently used data.

6. The method of claim 1, wherein said identifying the second block of data includes identifying least recently used data.

7. The method of claim 1, wherein said performing the data processing operations includes performing graphical operations.

8. The method of claim 1,

wherein the memory includes a first memory subsystem and a second memory subsystem;

wherein said identifying the second block of data stored in memory includes identifying the second block of data stored in the first memory subsystem;

wherein said storing the compressed second block of data in the memory includes storing the compressed second block of data in the second memory subsystem; and

wherein said storing the decompressed first block of data in the memory includes storing the decompressed first block of data in the first memory subsystem.

9. The method of claim 8,

wherein the first memory subsystem comprises system memory;

and

wherein the second memory subsystem comprises non-volatile memory.

10. A system, comprising:

one or more processors;

memory; and

a memory controller coupled to the one or more processors and to the memory, wherein the memory controller is configured to;

receive a request from the one or more processors for a first block of data;

in response to determining that the first block of data is stored in the memory as compressed data, identify a second block of data stored in the memory as uncompressed data;

free a portion of the memory by compressing the second block of data and storing the compressed second block of data in the memory;

decompress the first block of data; and

store the decompressed first block of data in the memory.

11. The system of claim 10, wherein the memory controller is further configured to identify the second block of data based on a likelihood that the second block of data will be requested.

12. The system of claim 10, wherein the memory controller is further configured to mark the decompressed first block of data as most recently used data.

13. The system of claim 10, wherein the memory controller is further configured to send the decompressed first block of data to the one or more processors.

14. The system of claim 10,

wherein the memory includes:

a first area corresponding to a first graphic display window; and

a second area corresponding to a second graphic display window; and

wherein the memory controller is further configured to store the decompressed first block of data by;

storing portions of the decompressed first block of data relating to the first graphic display window in the first area; and

storing portions of the decompressed first block of data relating to the second graphic display window in the second area.

15. The system of claim 10,

wherein the memory includes a first memory subsystem and a second memory subsystem;

wherein the identifying the second block of data stored in memory includes identifying the second block of data stored in the first memory subsystem;

wherein the storing the compressed second block of data in the memory includes storing the compressed second block of data in the second memory subsystem; and

wherein the storing the decompressed first block of data in the memory includes storing the decompressed first block of data in the first memory subsystem.

16. The system of claim 15,

wherein the first memory subsystem comprises system memory;

and

wherein the second memory subsystem comprises non-volatile memory.

17. An apparatus, comprising:

means for storing data;

means for requesting a first block of data that is stored as compressed data in the means for storing data;

means for freeing a portion of the means for storing data, responsive to a determination that the first block of data is stored as compressed data, by compressing a second block of data stored therein, and by storing the compressed second block of data in the means for storing data; and

means for decompressing the first block of data and causing the decompressed first block of data to be stored in the means for storing data.

18. The apparatus of claim 17, wherein the means for storing data includes a means for storing uncompressed data and a means for storing compressed data.

19. The apparatus of claim 17, wherein the apparatus is configured to mark the decompressed first block of data as most recently used data.

20. The apparatus of claim 17, wherein the apparatus is configured to select, based on the second block of data being identified as least recently used data, the second block of data for compressing.