| 摘要 |
PURPOSE:To improve the drawing performance by generating the write enable pattern of an image memory according to the pattern of data read out of a memory dedicated to a painting-out frame and using the page mode/read modify write cycle of the image memory. CONSTITUTION:A panting-out controller 18 and the memory 16 dedicated to the panting-cut frame, and the painting-out controller 18 and the image memory 12 are connected directly and respectively. The painting-out controller 18 supplies common RAS, CAS, and ADDRESS to the memory 16 dedicated to the painting-out frame and image memory 12 and reads data WDATA out of the memory 16 dedicated to the painting-out frame. The painting-out controller 18 after reading the WDATA out of the memory 16 supplies write enable WWE- to the memory 16 and write enable UWE- to the image memory 12 respectively and utilizes the page mode/read modify write cycle of the image memory 12 to write data obtained by interpolating the inside of an external frame. A converting circuit which is composed of EOR gates as a parallel type converts the WDATA pattern into the UWE pattern. Consequently, the drawing performance of the graphic display device is greatly improved. |
