Graphics memory system that utilizes detached-Z buffering in conjunction with a batching architecture to reduce paging overhead

A graphics memory system comprising:

• a first processing means for receiving and processing a first quantity of Z coordinates and pixel colors, each pixel color being associated with one location on a display screen, each Z coordinate representing a depth in 3-dimensional space of a pixel, each pixel color having a row and column address associated therewith, each row and column address corresponding to a memory location associated with one location on a display screen, each Z coordinate representing a depth in 3-dimensional space of a pixel, each pixel color having a row and column address associated therewith, each row and column address corresponding to a memory location in a first storage means such that each pixel color is associated with a particular memory location in the first storage means, the first processing means receiving a plurality of Z coordinates from the first storage means, the first processing means comparing each Z coordinate received from the first storage means with each Z coordinate of the first quantity in accordance with a Z comparison test to determine whether a pixel color associated with a compared Z coordinate of the first quantity should be written into the first storage means, wherein if the Z coordinate of the first quantity passes the Z comparison test, a determination is made that a pixel color associated with the compared Z coordinate of the first quantity that passed the Z comparison test is to be saved in the first storage means, wherein after the Z comparison test has been performed on all of the Z coordinates of the first quantity, pixel colors associated with the Z coordinates that passed the Z comparison test are saved in the first storage means at the memory location associated therewith, wherein the first storage means comprises an image buffer region and a Z buffer region, the image buffer region being separate from the Z buffer region, wherein Z coordinates are stored in the Z buffer region and pixel colors are stored in the image buffer region.

A method for processing Z coordinates and pixel colors in a graphics memory system, the method comprising:

• saving a plurality of Z coordinates in a frame buffer memory;
• saving a plurality of pixel colors in the frame buffer memory;
• receiving a quantity of new Z coordinates and new pixel colors in the graphics memory system, each of the new Z coordinates being associated with one of the new pixel colors;
• receiving a plurality of the new Z coordinates and a plurality of the new pixel colors in a first memory controller;
• reading a plurality of the Z coordinates out of the frame buffer memory into the first memory controller;
• comparing each of the Z coordinates read out of the frame buffer memory with one of the new Z coordinates in the first memory controller to determine whether each of the compared new Z coordinates passes or fails a Z comparison test;
• if one of the new Z coordinate passes the Z comparison test, storing the new Z coordinate that passed the Z comparison test in the frame buffer memory and storing the new pixel color associated with the Z coordinate that passed the Z comparison test in the frame buffer memory, wherein the frame buffer memory comprises an image buffer region and a Z buffer region, the image buffer region being separate from the Z buffer region, wherein Z coordinates are stored in the Z buffer region and pixel colors are stored in the image buffer region.