| 摘要 |
PURPOSE:To write image data at a high speed and to reduce the size of a copying machine by converting the image data into a parallel signal and storing the signal, and then transfering it to a memory for image data on the basis of DMA. CONSTITUTION:The image data from a sensor is converted by a conversion part 6 into the parallel digital signal, which is read, word by word, in the memory 8. Further, a counter 9 counts words written in the memory 8 and sets an FF10 when its counted value attains to a specific number, sending out a DMA request signal from its Q output. Consequently, a DMAC2 sends a request HOLD to a microcomputer 1 to enter DMA operation. The memory 8 uses a signal IOR from the DMAC2 as a shift-out clock signal during the DMA operation to transfer the image data from the memory 8 to an RAM3. This transfer data is written in a specific address of the RAM3 by using a signal MEMW from the microcomputer 1 as a clock signal. |
