Parallel pipeline graphics system

Abstract

The present invention relates to a parallel pipeline graphics system. The parallel pipeline graphics system includes a back-end configured to receive primitives and combinations of primitives (i.e., geometry) and process the geometry to produce values to place in a frame buffer for rendering on screen. Unlike prior single pipeline implementation, some embodiments use two or four parallel pipelines, though other configurations having 2̂n pipelines may be used. When geometry data is sent to the back-end, it is divided up and provided to one of the parallel pipelines. Each pipeline is a component of a raster back-end, where the display screen is divided into tiles and a defined portion of the screen is sent through a pipeline that owns that portion of the screen's tiles. In one embodiment, each pipeline comprises a scan converter, a hierarchical-Z unit, a z buffer logic, a rasterizer, a shader, and a color buffer logic.

1 . A graphics chip comprising:
 a front-end configured to receive one or more graphics instructions and to output a geometry;   a back-end configured to receive said geometry and to process said geometry into one or more final pixels to be placed in a frame buffer;   wherein said back-end comprises multiple parallel pipelines.   
     
     
         2 . The graphics chip of  claim 1  further comprising:
 a setup unit for directing said geometry into one of said multiple parallel pipelines.   
     
     
         3 . The graphics chip of  claim 2  wherein said geometry is determined to locate in a portion of an output screen defined by a tile. 
     
     
         4 . The graphics chip of  claim 1  wherein each of said parallel pipelines further comprises:
 a FIFO unit for load balanacing said each of said pipelines.   
     
     
         5 . The graphics chip of  claim 1  wherein each of said parallel pipelines further comprises:
 a scan converter;   a rasterizer;   a unified shader; and   a texture unit.   
     
     
         6 . The graphics chip of  claim 5  wherein each of said parallel pipelines further comprises:
 a z buffer logic unit; and   a color buffer logic unit.   
     
     
         7 . The graphics chip of  claim 6  wherein said z buffer logic unit interfaces with said scan converter through a hierarchical Z interface and an early Z interface. 
     
     
         8 . The graphics chip of  claim 6  wherein said z buffer logic unit interfaces with said unified shader through a late Z interface. 
     
     
         9 . A method for processing computer graphics comprising:
 receiving one or more graphics instructions in a front-end of a graphics chip and outputting a geometry;   receiving said geometry in a back-end of a graphics chip; and   processing said geometry into one or more final pixels to be placed in a frame buffer,   wherein said back-end comprises multiple parallel pipelines.   
     
     
         10 . The method of  claim 9  further comprising:
 using a setup unit to direct said geometry into one of said multiple parallel pipelines.   
     
     
         11 . The method of  claim 10  wherein said geometry is determined to locate in a portion of an output screen defined by a tile. 
     
     
         12 . The method of  claim 9  further comprising:
 using a FIFO unit for load balanacing each of said pipelines.   
     
     
         13 . The method of  claim 9  wherein each of said parallel pipelines further comprises:
 a scan converter;   a rasterizer;   a unified shader; and   a texture unit.   
     
     
         14 . The method of  claim 13  wherein each of said parallel pipelines further comprises:
 a z buffer logic unit; and   a color buffer logic unit.   
     
     
         15 . The method of  claim 14  wherein said z buffer logic unit interfaces with said scan converter through a hierarchical Z interface and an early Z interface. 
     
     
         16 . The method of  claim 14  wherein said z buffer logic unit interfaces with said unified shader through a late Z interface. 
     
     
         17 . A computer program product comprising:
 a computer usable medium having computer readable program code embodied therein configured to process computer graphics, said computer program product comprising:   computer readable code configured to cause a computer to receive one or more graphics instructions in a front-end of a graphics chip and output a geometry;   computer readable code configured to cause a computer to receive said geometry in a back-end of a graphics chip; and   computer readable code configured to cause a computer to process said geometry into one or more final pixels to be placed in a frame buffer,   wherein said back-end comprises multiple parallel pipelines.   
     
     
         18 . The computer program product of  claim 17  further comprises:
 computer readable code configured to use a setup unit to direct said geometry into one of said multiple parallel pipelines.   
     
     
         19 . The computer program product of  claim 18  wherein said geometry is determined to locate in a portion of an output screen defined by a tile. 
     
     
         20 . The computer program product of  claim 17  wherein said computer readable code configured to cause a computer to process further comprises:
 computer readable code configured to cause a computer to use a FIFO unit for load balanacing each of said pipelines.   
     
     
         21 . The computer program product of  claim 17  wherein said wherein each of said parallel pipelines further comprises:
 a scan converter;   a rasterizer;   a unified shader; and   a texture unit.   
     
     
         22 . The computer program product of  claim 21  wherein wherein each of said parallel pipelines further comprises:
 a z buffer logic unit; and   a color buffer logic unit.   
     
     
         23 . The computer program product of  claim 22  wherein said z buffer logic unit interfaces with said scan converter through a hierarchical Z interface and an early Z interface. 
     
     
         24 . The computer program product of  claim 22  wherein said z buffer logic unit interfaces with said unified shader through a late Z interface.