Abstract: An apparatus and method for controlling an asynchronous First-In-First-Out (FIFO) memory. The asynchronous FIFO has separate, free running read and write clocks. A number of n-bit circular Gray code counters are used to handshake the operation between read and write parts of the FIFO, wherein n is any integer more than one. Additional binary counters are used to accumulate the read and write overflows for the circular Gray code counters. When any circular Gray code counter is overflow, the read or write count is transferred to the respective binary counter for recording the FIFO accesses.

Abstract: The present invention, a method of the arbitration of memory request for a computer graphics system, consecutively services the requests having the same type in the same period, thereby increasing the chance of page-hit. In this arbitration method, the length of a fixed period is defined by the 3-D graphics engine in accordance with the amount of memory cycles or the amount of the requests, and is used for controlling the amount of the requests of each type. The length of the period can be the cycles of servicing a block comprising a tile or several tiles. Alternatively, instead of defining a fixed length of the period, the 3-D graphics engine can choose another arbitration method of the present invention. Another arbitration method of the present invention is to mark a message at the end of the drawing block, so that the memory control can decide to rotate the service order to the next type of requests according to the block-end message received.

Abstract: An apparatus and a method for supporting coexistence of an external AGP graphics adapter with an embedded graphics adapter. The embedded graphics adapter may be regarded as a PCI device, and the graphics memory of embedded graphics adapter is integrated into DRAM of a computer system. The corelogic and software capable of graphics address remapping and directed accessing graphics memory of the embedded graphics adapter for supporting external AGP graphics adapter and embedded graphics adapter respectively. The embedded graphics adapter could be an AGP device while the external graphics adapter would be a PCI device, and vice versa.

Abstract: A texture mapping method. First, the pixels are grouped into a plurality of pixel sets. For each pixel set, a unique texture coordinate is calculated according to the texture coordinates of each pixel in the pixel set. Then, a texture filtering process is perform according to the unique texture coordinate, so as to obtain a color value of the texture filtering. Finally, the color value is assigned to each of the pixels in the pixel set.

Abstract: The present invention discloses a method for accelerated triangle occlusion culling in the computer graphic system. The triangle-based visibility testing is determined by using a triangle within a particular group of Coarse-Z buffer. If the triangle within a particular group of Coarse-Z buffer is hidden, then the triangle will be discarded. By using triangle-based visibility pre- test determined by the Coarse-Z buffer, the graphics system can skip hidden surface at a great lick and the requirement of memory bandwidth and unnecessary computations is eliminated.