Data transfer from a graphics subsystem to system memory

• US 5,801,720 A
• Filed: 02/20/1996
• Issued: 09/01/1998
• Est. Priority Date: 02/20/1996
• Status: Expired due to Term

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Nanavati, Sameer Y., Norrod, Forrest E., Briggs, Willard S., Falardeau, Brian D., Wilcox, Christopher G.
• Primary Examiner(s): Kim, Matthew M.
• Assistant Examiner(s): CHAUHAN, ULKA J
• Application Number:
  US08/604,008
• Time in Patent Office: 924 Days
• Field of Search: 395/501, 395/503, 395/511, 395/512, 395/515, 395/520, 395/521, 395/525, 395/526, 395/480, 395/566, 395/842, 345/501, 345/503, 345/511, 345/512, 345/515, 345/520, 345/521, 345/525, 345/526, 711/6, 711/147-153, 711/202-207
• US Class Current: 345/568
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G09G 2360/125 using unified memory architecture [UMA]
• CPC Class Codes: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory

Abstract

A processing system includes a graphics subsystem that directly renders raster data to system memory and moves bitmaps between locations within system memory with the graphics subsystem providing the data and a processor providing the virtual-to-physical addresses with privilege and protection check mechanisms.

Claims

1. A method of transferring raster text from a graphics subsystem to a system memory with a processor comprising steps of:

(a) loading font information from the system memory into a blit buffer for each text character to be displayed;

(b) setting the graphics subsystem to read font information from the blit buffer;

(c) setting the graphics subsystem for source color expansion and to write raster text to the system memory; and

,

(d) without using a frame buffer as intermediate storage, moving the raster text directly from the graphics subsystem to the system memory while performing protection and privilege checks with the processor for each virtual address within the system memory being written.

2. A method of rendering a primitive in a graphics subsystem comprising steps of:

(a) from an application program executed on a processor, providing size and location information of the primitive to the graphics subsystem;

(b) from the application program, setting raster operation, color or monochrome pattern, color expansion, and transparency in the graphics subsystem;

(c) setting the graphics subsystem to write data to system memory; and

,

(d) without using a frame buffer as intermediate storage, recursively moving a block of data directly from the graphics subsystem to system memory while performing protection and privilege checking with the processor for each virtual-to-physical address being written within the system memory.

3. A system of transferring raster text from a graphics subsystem to a system memory with a processor comprising:

(a) means for loading font information from the system memory into a blit buffer for each text character to be displayed;

(b) means for setting the graphics subsystem to read information from the blit buffer;

(c) means for setting the graphics subsystem for source color expansion to write raster text to the system memory; and

,

(d) means, without using a frame buffer as intermediate storage, for moving the raster text directly from the graphics subsystem to the system memory while performing protection and privilege checks with the processor for each virtual address within the system memory being written.

4. A system of rendering a primitive in a graphics subsystem comprising:

(a) means for providing size and location information of the primitive to the graphics subsystem from an application program executed on a processor;

(b) means for setting raster operation, color or monochrome pattern, color expansion, and transparency in the graphics subsystem from the application program;

(c) means for setting the graphics subsystem to write data to system memory; and

,

(d) means, without using a frame buffer as intermediate storage, for recursively moving a block of data directly from the graphics subsystem to system memory while performing protection and privilege checking with the processor for each virtual-to-physical address being written within the system memory.

5. A processing system comprising:

(a) a processor;

(b) system memory coupled to the processor;

(c) a blit buffer coupled to the processor; and

,

(d) a graphics subsystem coupled to the processor wherein

(i) font information is loaded from the system memory into the blit buffer for each character to be displayed,

(ii) the graphics subsystem is set to read font information from the blit buffer,

(iii) the graphics subsystem is set for source color expansion and to write raster text to the system memory, and,

(iv) without using a frame buffer as intermediate storage, the raster text is moved directly from the graphics system to the system memory while performing protection and privilege checks with the processor for each virtual-to-physical address being written within the system memory.

6. A processing system comprising:

(a) a processor;

(b) system memory coupled to the processor;

(c) a blit buffer coupled to the processor; and

,

(d) a graphics subsystem coupled to the processor wherein

(i) size and location information of a graphic primitive is provided to the graphics subsystem from an application program;

(ii) raster operation, color or monochrome pattern, color expansion, and transparency is set in the graphics subsystem from the application program;

(iii) the graphics subsystem is set to write data to system memory; and

,

(iv) without using a frame buffer as intermediate storage, a block of data from the graphics subsystem is recursively moved to system memory while performing protection and privilege checking with the processor for each virtual-to-physical address being written within the system memory.

7. A computer system comprising:

(a) a motherboard;

(b) a central processing unit disposed on the motherboard;

(c) memory disposed on the motherboard and coupled to the central processing unit; and

,

(d) a graphics subsystem coupled between the central processing unit and the memory wherein

(i) font information is loaded from the memory into a blit buffer for each text character to be displayed,

(ii) the graphics subsystem is set to read font information from the blit buffer,

(iii) the graphics subsystem is set to write raster text to the system memory, and,

(iv) without using a frame buffer as intermediate storage, the raster text is moved directly from the graphics system to the system memory while performing protection and privilege checks with the central processing unit for each virtual-to-physical address being written within the system memory.

8. A computer system comprising:

(a) a motherboard;

(b) a central processing unit disposed on the motherboard;

(c) memory disposed on the motherboard and coupled to the central processing unit; and

,

(d) a graphics subsystem coupled between the central processing unit and the memory wherein

(i) size and location information of a graphic primitive is provided to the graphics subsystem from an application program;

(ii) raster operation, color or monochrome pattern, color expansion, and transparency is set in the graphics subsystem from the application program;

(iii) the graphics subsystem is set to write data to the memory; and

,

(iv) a block of data from the graphics subsystem is recursively moved by the central processing unit to the memory while performing protection and privilege checking with the central processing unit for each virtual-to-physical address being written within the memory without using a frame buffer as intermediate storage.

9. In a computer having a motherboard, a central processing unit, a subsystem, and system memory external to the central processing unit, a method of transferring raster text comprising the steps of:

(a) loading font information from the system memory into a blit buffer for each text character to be displayed;

(b) setting the graphics subsystem to read font information from the blit buffer;

(c) setting the graphics subsystem for source color expansion and to write raster text to the system memory; and

,

(d) without using a frame buffer as intermediate storage, moving the raster text directly from the graphics subsystem to the system memory while performing protection and privilege checks with the central processing unit for each virtual-to-physical address within the system memory being written.

10. In a computer having a motherboard, a central processing unit, a subsystem, and system memory external to the central processing unit, a method of performing a primitive in a graphics subsystem comprising steps of:

(a) from an application program, providing size and location information of the primitive to the graphics subsystem;

(b) from the application program, setting raster operation, color or monochrome pattern, color expansion, and transparency in the graphics subsystem;

(c) setting the graphics subsystem to write data to system memory; and

,

(d) without using a frame buffer as intermediate storage, recursively moving a block of data from the graphics subsystem to system memory while performing protection and privilege checking with the central processing unit for each virtual-to-physical address being written within the system memory.