| 摘要 |
<p>PURPOSE:To shorten the DMA transfer time of a microcomputer having the DMA transfer function. CONSTITUTION:A DMAC consists of a main DMAC 5 and a local DMAC 6, and the DMA transfer address of a memory 2 is designated through a main address bus 21 by the main DMAC 5, and the DMA transfer address or an I/O 3 us designated through a local address bus 22 by the local DMAC 6 synchronously with this operation. Since DMA transfer which requires two memory cycles in the conventional method is performed in one memory cycle without temporarily storing data in an internal register or the like, the DMA transfer time is shortened.</p> |
