| 摘要 |
PURPOSE:To change all data of one picture element with one read update, and write processing by subjecting only bits of a prescribed picture element of display data to logical operation for plotting and writing the result in a display memory again. CONSTITUTION:An arithmetic unit 30 successively calculates a picture element address consisting of information, which designates an address of a display memory 13 and the picture element position in display data of one word in the display memory 13, and reads out display data of one word in the display memory 13 in accordance with address information of the display memory 13 in the calculated picture element address. Only bits of a prescribed picture element of display data read out in this manner are subjected to logical operation for plotting with information which designates plural bit positions corresponding to the designated picture element position generated by decoding based on picture element position designating information in the picture element address, and the logical operation result is written in the display memory 13 again. |
