Graphical data access method apparatus and system

Abstract

Graphical memory access requests are routed to a plurality of bucket buffers. Filled bucket write buffers and empty bucket read buffers are efficiently emptied and filled respectively via a wide memory bus. The bucket sorting apparatus and method is used to increase the locality of memory references and pixel operations within a graphical rendering system. The increased locality increases graphical rendering performance and facilitates the usage of smaller z-buffers, larger tiles, and low-cost dynamic RAM within a graphics pipeline.

1 . An apparatus for increasing the access locality of graphical rendering data, and discarding non-visible pixel descriptors in a graphical system, the apparatus comprising: 
 a region memory configured to store pixel descriptors;    a region sorter configured to receive pixel descriptors including scene position and depth, and to direct the pixel descriptors to locations within the region memory corresponding to regions within a graphical scene; and    a region-sized z-buffer configured to receive the pixel descriptors and to retain the pixel descriptor with the shallowest pixel depth for each position within a graphical scene region.    
     
     
         2 . The apparatus of  claim 1 , wherein the z-buffer is further configured to retain more than one pixel descriptor for each screen position.  
     
     
         3 . The apparatus of  claim 1 , wherein the region sorter comprises: 
 at least one sorter input port configured to receive rendering data;    a plurality of bucket buffers configured to transfer the rendering data to the region memory; and    a bucket controller configured to select a portion of the rendering data as a bucket key and to direct the rendering data from each sorter input port to the bucket buffer corresponding to the bucket key.    
     
     
         4 . A method for increasing the access locality of graphical rendering data and discarding non-visible pixels in a graphical system, the method comprising: 
 sorting pixel descriptors into a plurality of regions based on scene position; and    processing the pixel descriptors within a region using a region-sized z-buffer.    
     
     
         5 . The method of  claim 4 , wherein sorting the pixel descriptors comprises at least one level of bucket sorting.  
     
     
         6 . An apparatus for increasing the locality of references to locations within a graphics memory, the apparatus comprising: 
 a graphics memory configured to store data within a plurality of memory pages;    an access request memory partitioned into a plurality of page access queues; and    a request sorter configured to receive requests to access the graphics memory, determine an associated memory page, and direct each request to the page access queue corresponding to the associated memory page.    
     
     
         7 . The apparatus of  claim 6 , wherein the request sorter comprises: 
 at least one sorter input port configured to receive rendering data;    a plurality of bucket buffers configured to transfer the rendering data to the graphics memory; and    a bucket controller configured to select a portion of the rendering data as a bucket key and to direct the rendering data from each sorter input port to the bucket buffer corresponding to the bucket key.    
     
     
         8 . A method for increasing access locality within a graphics memory, the method comprising: 
 sorting a plurality of access requests into a plurality of page queues; and    processing the access requests within a page queue.    
     
     
         9 . The method of  claim 8 , wherein sorting a plurality of access requests comprises at least one level of bucket sorting.  
     
     
         10 . An apparatus for increasing the access locality of pixel attribute data within a graphical system, the apparatus comprising: 
 a pixel attribute memory configured to store pixel attribute data within a plurality of memory pages;    an attribute request memory partitioned into a plurality of attribute request queues; and    a request sorter configured to receive requests to access a storage location within the pixel attribute memory and direct the requests to the attribute request queue corresponding to the storage location.    
     
     
         11 . The apparatus of  claim 10 , wherein the request sorter comprises: 
 a plurality of bucket buffers configured to transfer data to the pixel attribute memory;    at least sorter input port configured to receive rendering data; and    a bucket controller configured to select a portion of the rendering data as a bucket key and to direct the rendering data from each sorter input port to the bucket buffer corresponding to the bucket key.    
     
     
         12 . The apparatus of  claim 10 , further comprising a colorizer configured to receive pixel attribute data and modify the color of pixels in accordance with the pixel attribute data.  
     
     
         13 . A method for increasing the access locality of pixel attribute data to efficiently colorize pixels within a graphical system, the method comprising: 
 sorting a plurality of pixel attribute requests into a plurality of page queues;    processing the pixel attribute requests within a page queue to provide pixel attributes; and    colorizing pixels based on the pixel attributes.    
     
     
         14 . The method of  claim 13 , wherein sorting comprises at least one level of bucket sorting.  
     
     
         15 . The method of  claim 13 , wherein colorizing is selected from shading, texturing, color table indexing, and shadowing.