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

• US 8,176,288 B2
• Filed: 01/14/2009
• Issued: 05/08/2012
• Est. Priority Date: 11/16/1994
• Status: Expired due to Fees

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Mossman Holdings LLC (Intellectual Ventures LLC)
• Inventors: Dye, Thomas A.
• Primary Examiner(s): KIM, HONG CHONG
• Application Number:
  US12/353,907
• Publication Number:
  US 20090125698A1
• Time in Patent Office: 1,210 Days
• Field of Search: 711/170, 711/159, 711/160, 345/530, 345/555, 710/68, 709/247, 708/203, 382/244
• US Class Current: 711/170
• 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) preferably sits on the main CPU bus or a high speed system peripheral bus and couples 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 formal 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 for managing memory in a system including a CPU, a system memory for storing applications and data, and a memory controller coupled between the CPU and the system memory, wherein the memory controller performs memory control functions for the system memory, wherein the memory controller includes a hardware compression engine and a graphics engine, the method comprising:

the memory controller receiving a request for a first block of data;

in response to determining that the requested first block of data is stored in the system memory in the compressed format, the memory controller identifying a second block of data stored in the system memory in the uncompressed format, wherein said identifying is based at least in part on a determined likelihood that the identified second block of data will be accessed;

the memory controller receiving the uncompressed second block of data from the system memory, wherein the system memory is a volatile memory that stores at least a portion of data in a compressed format and stores at least a portion of data in an uncompressed format;

the hardware compression engine in the memory controller freeing a portion of the system memory by compressing the second block of data to produce a compressed second block of data and storing the compressed second block of data in the system memory;

the hardware compression engine in the memory controller decompressing the first block of data;

the memory controller storing the decompressed requested first block of data in the system memory in the uncompressed format; and

the graphics engine in the memory controller performing graphical operations using at least a portion of the decompressed first block of data, wherein said performing graphical operations includes;

mapping a first area of the system memory to first information related to a first graphic display window of a display, wherein adjusting the location within the display of the first graphic display window is accomplished without moving the first information to an area of the system memory other than the first area; and

mapping a second area of the system memory to second information related to a second graphic display window of the display, wherein adjusting the location within the display of the second graphic display window is accomplished without moving the second information to area of the system memory other than the second area;

wherein the first area and the second area are not identical.

2. A system, comprising:

a CPU;

a system memory configured to store uncompressed data and compressed data, wherein the system memory is a volatile memory;

a memory controller coupled to the CPU and to the system memory, wherein the memory controller performs memory control functions for the system memory, wherein the memory controller includes a hardware compression engine and a graphics engine;

wherein the memory controller is configured to;

in response to receiving a request for a first block of data, determine whether the first block of data is stored in the system memory as compressed data;

in response to determining that the first block of data is stored in the system memory as compressed data, identify a second block of data stored in the system memory as uncompressed data based at least in part on a determined likelihood that the second block of data will be accessed;

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

decompress the first block of data and store the decompressed first block of data in the system memory; and

perform graphical operations using at least a portion of the decompressed first block of data to produce video display data, wherein the graphical operations include;

mapping a first area of the system memory to first information related to a first graphic display window of a display, wherein adjusting the location within the display of the first graphic display window is accomplished without moving the first information to an area of the system memory other than the first area; and

mapping a second area of the system memory to second information related to a second graphic display window of the display, wherein adjusting the location within the display of the second graphic display window is accomplished without moving the second information to area of the system memory other than the second area;

wherein the first area and the second area are not identical.

3. The system of claim 2, wherein the system is configured to provide the video display data to a device.

4. The system of claim 2, wherein the decompressed first block of data includes the first information and the second information.

5. The system of claim 2, wherein the memory controller is further configured to:

receive an additional uncompressed block of data from a nonvolatile memory;

compress the additional uncompressed block of data to produce an additional compressed block of data; and

store the additional compressed block of data in the system memory.

6. The system of claim 2, wherein the graphical operations that the memory controller is configured to perform comprise:

rendering polygons;

interpolating objects; and

performing font conversion.

7. The system of claim 2, wherein the system memory stores most recently used data in an uncompressed format, and wherein the memory controller is further configured to mark the decompressed first block of data as the most recently used data.

8. The system of claim 2, wherein the memory controller is configured to identify the second block of data by identifying least recently used data.

9. The system of claim 2,

wherein the memory controller compressing the second block of data comprises the hardware compression engine performing lossless compression to produce the compressed second block of data.

10. The system of claim 2,

wherein the hardware compression engine is configured to perform lossless compression;

and

wherein the memory controller storing the compressed second block of data includes replacing the uncompressed second block of data in the system memory.

11. The system of claim 2, wherein said performing graphical operations includes formatting data to adjust coordinate addressing.

12. A method, comprising:

a memory controller receiving a request for a first block of data, wherein the memory controller is coupled to a system memory storing uncompressed data and compressed data, wherein the system memory is a volatile memory;

the memory controller determining whether the first block of data is stored in the system memory as compressed data;

in response to determining that the first block of data is stored in the system memory as compressed data, the memory controller identifying a second block of data stored in the system memory as uncompressed data, wherein the identifying is based at least in part on a determined likelihood that the second block of data will be accessed;

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

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

the memory controller performing graphical operations using at least a portion of the decompressed first block of data, wherein said performing graphical operations includes;

mapping a first area of the system memory to first information related to a first graphic display window of a display, wherein adjusting the location within the display of the first graphic display window is accomplished without moving the first information to an area of the system memory other than the first area; and

mapping a second area of the system memory to second information related to a second graphic display window of the display, wherein adjusting the location within the display of the second graphic display window is accomplished without moving the second information to area of the system memory other than the second area;

wherein the first area and the second area are not identical.

13. The method of claim 12, wherein the decompressed first block of data includes the first information and the second information.

14. The method of claim 12, further comprising:

the memory controller receiving an additional uncompressed block of data from a nonvolatile memory;

the memory controller compressing the additional uncompressed block of data to produce an additional compressed block of data; and

the memory controller storing the additional compressed block of data in the system memory.

15. The method of claim 12, wherein said performing graphical operations comprises:

rendering polygons;

interpolating objects; and

performing font conversion.

16. The method of claim 12, wherein the system memory stores most recently used data in an uncompressed format, and wherein the storing the decompressed first block of data includes marking the decompressed first block of data as the most recently used data.

17. The method of claim 12, wherein said identifying the second block of data includes identifying least recently used data.

18. The method of claim 12, wherein said compressing the second block of data is performed by a hardware compression engine.

19. The method of claim 18, wherein said compressing the second block of data comprises the hardware compression engine performing lossless compression to produce the compressed second block of data.

20. The method of claim 12, wherein said decompressing the first block of data comprises decompressing CPU application data.

21. The method of claim 12,

wherein said compressing and said decompressing are performed by a hardware compression/decompression engine;

and

wherein said storing the compressed second block of data comprises replacing the uncompressed second block of data in the system memory.

22. The method of claim 12, wherein said performing graphical operations comprises formatting data to adjust coordinate addressing.