Method and apparatus for pattern ram sharing color look up table

Abstract

A method and apparatus for sharing the video memory of a graphic chip includes the steps as follows: when the destination block of a frame buffer executes color expansion, storing a color LUT to a memory shared by both pattern and color LUT in a video memory, so as to provide color expansion; and when the graphic engine accesses a pattern memory, storing a pattern block to the memory shared by both pattern and color LUT for the access of a graphic engine. By the above-mentioned sharing mechanism, the physical layout area of the graphic chip is reduced and the cost also drops.

1 - 6 . (canceled)  
   
   
       7 . A graphic chip with a sharing video memory comprising: 
 a video memory for storing one sharing memory of a pattern and color LUT at least, and a content of said sharing memory of pattern and color LUT is adjusted in accordance with an access apparatus; and    a graphic engine for accessing and processing a plurality of pattern blocks of said sharing memory of pattern and color LUT.    
   
   
       8 . The graphic chip with a sharing video memory as recited in  claim 7  comprising: 
 a graph and video overlapping unit for receiving and overlapping a destination block of a frame buffer and a graph and video source.    
   
   
       9 . The graphic chip with a sharing video memory as recited in  claim 7  comprising: 
 a frame buffer for storing a destination block at least for a graph and video overlapping unit to perform an overlapping procedure.    
   
   
       10 . The graphic chip with a sharing video memory as recited in  claim 7 , wherein if the access apparatus is a frame buffer, said sharing memory of pattern and color LUT provided for storing said color LUT, whereas if the access apparatus is said graphic engine, said sharing memory of pattern and color LUT provided for storing said plurality of said pattern blocks.