| 摘要 |
PROBLEM TO BE SOLVED: To quickly transfer image data on a memory to a print engine by DMA(direct memory access) in an image forming device. SOLUTION: Image data on a DRAM 21 are transferred to a print engine 27 by a DMA controller 13. Image data in each page are divided into plural bands, and each band data are transferred by one DMA operation. A CPU 23 sets a parameter such as the start address of each band or the number of band bytes prior to each time DMA transfer, and a DMA controller 13 operate a DMA operation by loading the parameter each time. At each parameter setting, the CPU 23 sets a continuity flag for indicating whether or not continuous DMA should be operated in the DMA controller 13. As long as the continuity flag is '1', the DMA controller 13 repeats the execution of the load of the parameter and the DMA operation. In this case, the CPU 23 sets a parameter for the next time DMA operation during each time DMA operation. Therefore, the DMA transfer of the plural bands can be executed continuously, without intervals.
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