High speed RAMDAC with reconfigurable color palette

摘要

A method and apparatus for generating both a true color and fast pseudo color video signals includes the combination of first and second commercially available RAMDACs. Parallel video data representing the red, blue, and green color components of one or more pixels is provided on a video bus to the inputs of the first and second RAMDACs. A first data portion of the parallel video data is presented to the input of the first RAMDAC, which can represent either a single pixel in the fast pseudo color mode or the most significant pixel data. A second data portion of the parallel video data is presented to the input of the second RAMDAC, which can represent either another single pixel in the fast pseudo color mode or the least significant pixel data. The outputs of the two RAMDACs are combined to provide true color video signals in a first RAM programming mode, and the respective outputs of the two RAMDACs are multiplexed to provide fast pseudo color video signals in a second RAM programing mode.