| 摘要 |
PURPOSE:To handle two-dimensional data at a high speed and alter easily the dimension such as a longitudinally long, a laterally long, and a square shape, etc., by performing DMA (dynamic memory access) transfer in an optional rectangular area in a linear memory by one-time parameter setting and starting. CONSTITUTION:Data DELTA(x), P(x), P(y), and DELTA(y) on an image are inputted from a bus 16 to initial value registers 5-7 and a counter 14. The starting point of the image is indicated with the initial value of the data P(x) and P(y), the data DELTA(x) is counted 10 with a clock signal, and the address of the data P(x) is counted 11; once X-directional DMA is completed, an Y-directional shift is made, and the X-directional DMA is repeated until the DELTA(y) counter 14 attains to a specific value. Then, the X and Y position and ratio X/Y are indicated to a shifting circuit 8 and a decoder 13 with the output of an X and Y size control register 9. The outputs of P(x) and P(y) address counters 11 and 12 and the output of a decoder 13 are multiplexed 15 to alter the longitudinal/lateral ratio of a rectangle at a high speed. |
