| 摘要 |
PURPOSE:To change all data equivalent to 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:Color data and data or the like are 4-bit color information and gradation information respectively, and pattern information is read out for one bit from a pattern memory 220, and a color register 0 or 1 is selected in accordance with '0' or '1' of this data to supply its contents to a logical operation device 3305. In this logical operation device 3305, only a part designated by bit '1' of GMSK (register) in a mask register 3303 is subjected to logical operation to obtain write data Cy, and it is stored in a write buffer 3306. Address information AD and data DT are sent from an address register 3311 and a register 3306 to an output bus 3312 in this order again and are written in a prescribed address of the display memory. |
