PURPOSE:To speedily develop the color code of a foreground or background color by holding the color code of the foreground color in a foreground color register and the color code of the background color in a background color register, and using them repeatedly. CONSTITUTION:The foreground color register 11 of a color code developing circuit is a register which holds the color code of the foreground color and the background color register 12 holds the color code of the background color. A pattern rotator 13 holds pattern data to be developed into a color code and rotates said pattern data. The pattern rotator 13 rotates the data so that the most significant digit bit and the least significant digit bit are coupled with each other, so the pattern data to be developed into the color code is held and also outputted repeatedly. A code selector 14 selects and outputs the color code of said foreground or background color according to the contents of the high-order digit bits of a shift register 13.
展开▼
