Patent Number: 6,295,068

Title: Advanced graphics port (AGP) display driver with restricted execute modefor transparently transferring textures to a local texture cache

Abstract: A graphics system includes an accelerated graphics port (AGP) bus to thegraphics accelerator. The graphics accelerator includes a 3D-graphicsengine that renders textures, and a local graphics memory. Preferably, thelocal graphics memory is an embedded DRAM on the graphics-acceleratorchip. A portion of the personal computer's main memory is set aside as anAGP memory for storing textures for 3D-graphics rendering. High-levelapplication programs create textures in the AGP memory. A 3D graphicssoftware driver that controls the graphics accelerator manages a texturecache in the local graphics memory. When the high-level applicationrequests that the 3D graphics driver render a texture in the AGP memory,the 3D graphics driver moves the texture to the texture cache. Once thetexture has been copied from the AGP memory, over the AGP bus to thetexture cache in the local graphics memory, the 3D graphics engine beginsrendering the texture. The 3D graphics driver manages the texture cache,invalidating least-recently-used textures and de-fragmenting blocks oftextures in the texture cache. The 3D driver transfers the texture to thetexture cache, rather than the high-level application. The high-levelapplication is not aware of the texture cache and can use a single handleto the texture. The benefits of the AGP Execute model are achieved withoutadding AGP-texturing hardware to the 3D graphics accelerator.

Inventors: Peddada; Vijay (Fremont, CA), Ranade; Shreekant M. (Sunnyvale, CA)


International Classification:

Expiration Date: 09/25/2013