| 摘要 |
PROBLEM TO BE SOLVED: To enable displaying simultaneously a bit map, a graphic, a still picture, a motion video picture, or a background on a display screen by selecting data bits from a FIFO(fast in fast out memory) and forming the present pixels. SOLUTION: A frame memory including a page to be displayed is arranged at an external memory, and this memory is preferably a SDRAM(screen display RAM). A OSD(on screen display) coprocessor comprises a display controller, a FIFO, an attribute memory, a window controller, a decoder, a line counter, and pixel counter. The display controller reads out a frame memory for each block and transfer it to the FIFO. The decoder reads out bits required for displaying the present pixels from the FIFO for each pixel. A pixel selector and its controller select bits of data from the FIFO, and form the present pixels. |
