Abstract: A 3D rendering texture caching scheme that minimizes external bandwidth requirements for texture and increases the rate at which textured pixels are available. The texture caching scheme efficiently pre-fetches data at the main memory access granularity and stores it in cache memory. The data in the main memory and texture cache memory is organized in a manner to achieve large reuse of texels with a minimum of cache memory to minimize cache misses. The texture main memory stores a two dimensional array of texels, each texel having an address and one of N identifiers. The texture cache memory has addresses partitioned into N banks, each bank containing texels transferred from the main memory that have the corresponding identifier. A cache controller determines which texels need to be transferred from the texture main memory to the texture cache memory and which texels are currently in the cache using a least most recently used algorithm.

Abstract: A pipeline apparatus for processing 3D graphics data will be described. The pipeline apparatus includes a first request memory to fetch information corresponding to a texture operand. A second request memory fetches information responding to a color operand and Z operand. A control circuit coordinates data flow from the first request memory and the second request memory into a memory channel by preventing the number of requests from the first request memory from exceeding by a predetermined number, the number of requests from the second request memory. By properly coordinating the data flow, deadlock of a data fetching pipeline is avoided.