Memory organization apparatus and method

• US 4,745,407 A
• Filed: 10/30/1985
• Issued: 05/17/1988
• Est. Priority Date: 10/30/1985
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Costello, Peter W.
• Primary Examiner(s): Brigance, Gerald L.
• Application Number:
  US06/792,795
• Time in Patent Office: 930 Days
• Field of Search: 340/798, 340/799, 340/703, 340/750, 340/723
• US Class Current: 345/550
• CPC Class Codes: G09G 5/022 using memory planes
• CPC Class Codes: G09G 5/363 Graphics controllers
• CPC Class Codes: G09G 5/39 Control of the bit-mapped memory
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence

Abstract

An improved memory organization for use in a computer display system including a display having a plurality of display pixels for defining images that includes: a frame buffer memory having a plurality of memory cells organized into a matrix, said memory comprising first and second maps wherein the contents of the maps correspond to the pixels and define characteristics of the pixels, the maps being defined along X and Z axes of the matric; reading means coupled to the frame buffer memory for selectively reading, in one memory cycle operation, a plurality of bits from memory cells defining one of the maps; writing means coupled to said frame buffer memory for selectively storing, in one memory cycle operation, a plurality of bits into memory cells defining one of the maps; control logic means coupled to the reading means and the writing means for generating control signals for selectively reading a plurality of bits from one of the maps and writing a plurality of bits into one of the maps to define the images to be displayed on said display; wherein multiple maps may be defined in an array of memory cells, each of the maps providing different characteristics for the pixels of the display.

Claims

1. An improved memory organization for use in a computer display system including a display having a plurality of display pixels for defining images, comprising:

a frame buffer memory having a plurality of selectively addressable memeory cells organized into a three-dimensional matrix, wherein each of said memory cells is adapted for storing a data bit defining selected characteristics of a corresponding display pixel and wherein said memory cells are relatable by a first bit organization oriented in a first plane of said matirx and a second bit organization orientied in a second plane of said matrix;

said first and second bit organizations defining, respectively, first and second characteristics among said selected characteristics;

reading means coupled to said frame buffer memory for selectively reading, in one memory cycle operation, a plurality of bits from memory cells related by one of said bit organizations and defining one of said first or said second characteristics;

writing means coupled to said frame buffer memory for selectively writing, in one memory cycle operation, a plurality of bits into memory cells related by one of said bit organizations and defining one of said first or second characteristics;

control logic means coupled to said reading means and said writing means for generating control signals for controllably selecting one of said first and second bit organizations;

whereby image data may be conveniently organized in a single memory array for selective storage and retrieval in one of said first and second bit organizations so as to provide said selected characteristics of said pixels.

2. The improved memory organization as claimed in claim 1 wherein said matrix comprises:

a plurality of X-Y planes, each of said planes containing a plurality of memory cells, said memory cells of each plane having a one-to-one correspondence with said display pixels, wherein a first plurality of data units defining first display pixel characteristics are aligned along an X-axis and of said X-Y planes; and

wherein said X-Y planes are aligned along a Z-axis such that a second plurality of data units defining second display pixel characteristics are aligned along said Z-axis.

3. The improved memory organization of claim 2 wherein said plurality of X-Y planes are consecutively aligned such that a first data bit on one plane corresponds to a second data bit on an adjacent plane such that said corresponding bits aligned along said Z-axis comprise one of said second plurality of data units.

4. The improved memory organization of claim 3 wherein said first plurality of data units and said second plurality of data units are stored within the same memory cells of said frame buffer.

5. The improved memory organization of claim 2 wherein said control logic means comprises:

a first address driver, coupled to said frame buffer, for issuing a first plurality of address signals to said frame buffer such that said first address driver issues a separate address for each of said first plurality of data units, thereby determining a memory location within a first predetermined segment of said frame buffer for each of said first plurality of data units;

a control logic device for issuing, in conjunction with said first plurality of address signals issued by said first address driver, a first plurality of frame buffer enabling signals to said frame buffer for enabling;

said first predetermined segment of said frame buffer

whereby, said first plurality of digital values are organized, such that a first map is defined within said frame.

6. The improved memory organization of claim 5 wherein said control logic means further comprises:

a second address driver, coupled to said frame buffer, for issuing a second plurality of address signals to said frame buffer such that said second address driver issues a separate address for each of said second plurality of data units, thereby determining a memory location within a second predetermined segment of said frame buffer for each of said second plurality of data units;

wherein said control logic device issues to said frame buffer, in conjunction with said second plurality of address signals issued by said second address driver, a second plurality of frame buffer enabling signals for enabling said second predetermined segment of said frame buffer.

7. The improved memory organization as claimed in claim 1 wherein said reading means comprises:

a first address driver, coupled to said frame buffer, for issuing a first plurality of address signals to said frame buffer such that said first address driver issues a separate address for each of said first plurality of data units, thereby determining a memory location within a first predetermined segment of said frame buffer for each of said first plurality of data units;

said control logic means issuing, in conjunction with said first plurality of address signals issued by said first address driver, a first plurality of frame buffer enabling signals to said frame buffer for enabling said first predetermined segment of said frame buffer;

a first memory logic means coupled to said frame buffer for receiving said first address signals and said first plurality of frame buffer enabling signals and retrieving said first plurality of data bytes in response thereto; and

a first data driver coupled to said frame buffer for sensing and outputting a desired one of said first plurality of data units in conjunction with said first plurality of address signals and said first plurality of frame buffer enabling signals.

8. The improved memory organization as claimed in claim 7 wherein said reading means further comprises:

a second address driver, coupled to said frame buffer, for issuing a second plurality of address signals to said frame buffer such that said second address driver issues a separate address for each of said second plurality of data units, thereby determining a memory location within a second predetermined segment of said frame buffer for each of said second plurality of data units;

said control logic means issuing, in conjunction with said second plurality of address signals issued by said second address driver a second plurality of frame buffer enabling signals to said frame buffer for enabling said second predetermined segment of said frame buffer;

a second memory logic means coupled to said frame buffer for receiving said second address signals and said second plurality of frame buffer enabling signals and retrieving said second plurality of data units in response thereto; and

a second data driver coupled to said frame buffer for sensing and outputting a desired one of said second plurality of data units in conjunction with said second plurality of address signals and said second plurality of frame buffer enabling signals.

9. The improved memory organization as claimed in claim 1 wherein said writing means comprises:

a first address driver, coupled to said frame buffer, for issuing a first plurality of address signals to said frame buffer such that said first address driver issues a separate address signal for each of said first plurality of data units, thereby determining a memory location within a first predetermined segment of said frame buffer for each of said first plurality of data units;

said control logic means issuing, in conjuntion with said first plurality of address signals issued by said first address driver, write enable signals and a first plurality of frame buffer enabling signals for enabling said first predetermined segment of said frame buffer and for permitting writing therein;

a first data driver coupled to said frame buffer for sensing and outputting a desired one of said first plurality of data units in conjunction with said first plurality of address signals;

wherein said first data driver writes a desired one of said first plurality of data units into said frame buffer at a memory location therein determined by said first plurality of address signals, said first plurality of frame buffer enabling signals and said write enable signals.

10. The improved memory organization of claim 9 wherein said writing means further comprises;

a second address driver coupled to said frame buffer, for issuing a second plurality of address signals to said frame buffer such that said second address driver issues a separate address signal for each of said second plurality of data units, thereby determining a memory location within a second predetermined segment of said frame buffer for each of said second plurality of data units;

said control logic means issuing, in conjunction with said second plurality of address signals issued by said second address driver, write enable signals and a second plurality of frame buffer enabling signals for enabling said second predetermined segment and for permitting writing therein;

a second data driver for sensing and outputting a desired one of said second plurality of data units in conjunction with said second plurality of address signals and said second plurality of frame buffer enabling signals;

wherein said second data driver writes a desired one of said second plurality of data units into said frame buffer at a memory location therein determined by said second plurality of address signals, said second plurality of frame buffer enabling signals and said write enable signals.

11. The improved memory organization of claim 1 wherein each data bit determines background/foreground of a corresponding one of said pixels.

12. The improved memory orgaization of claim 2 wherein said second plurality of data units determines a color at a corresponding one of said pixels.

13. The improved memory organization of claim 1 further comprising:

a raster logic processor, coupled between said reading means and said writing means for reading and writing a plurality of data bytes in alternate memory cycle operations.

14. The improved memory organization of claim 1 further comprising a per plane write mask coupled to said frame buffer, for masking a desired number of bits of a one of said second plurality of data bytes when said second plurality of data bytes are being written into said frame buffer.

15. The improved memory organization of claim 7 wherein said first data driver multiplexes said first plurality of data bytes.

16. The improved memory organization of claim 8 wherein said second data driver multiplexes said second plurality of data bytes.

17. The improved memory organization of claim 1 further comprising:

an optional frame buffer, coupled to said writing means, said reading means and said control logic means, wherein said optional frame buffer may be written to while said frame buffer is being read from and the reverse thereof.

19. The improved memory organization of claim 4, wherein said reading means, said writing means and said control logic means are comprised in a monolithic integrated circuit.

18. An improved method of organizing a memory for use in a computer display system including a display having a plurality of display pixels for defining images, said method comprising the steps of:

organizing a frame buffer memory having a plurality of selectively addressable memory cells, wherein each of said memory cells is adapted for storing data defining selected characteristics, into a three-dimensional matrix such that said memory cells are relatable by a first bit organization, which is oriented in a first plane of said matrix and a second bit organization oriented in a second plane of said matrix;

said first and second bit organizations defining, respectively, first and second characteristics among said selected characteristics;

corresponding the contents of said memory cells to said pixels;

coupling a reading means to said frame buffer for selectively reading, in one memory cycle operation, a plurality of bits from memory cells relatable by one of said bit orgaizations;

reading selectively said plurality of bits from one of said bit organizations from said frame buffer with said reading means;

coupling a writing means to said frame buffer memory, for selectively writing, in one memory cycle operation, a plurality of bits into memory cells relatable by one of said bit organizations;

writing selectively said plurality of bits from one of said bit organization to define a selected one of said characteristics into said frame buffer with said writing means;

coupling a control logic means to said reading means and said writing means and said frame buffer;

generating control signals for selecting one of said bit organizations to define said images to be displayed on said display.