| 摘要 |
PROBLEM TO BE SOLVED: To stably perform DMA transfer at one word unit regardless of the amount of data transfer at a data transmission side and a data transfer destination address at a data receiving side in a data transfer device storing data from the transmission side to a FIFO memory in sequence and reading out data from the FIFO memory at a receiving side. SOLUTION: Front one byte of data stored in a FIFO 24 is copied in a monitor register MR before DMA transfer. Data in the FIFO 24 is carried out DMA transfer to RAM 22 by every one word with an even-number address of a reading start address as well as a writing start address of the RAM 22. When a non-transferred data number becomes one byte, the DMA transfer is interrupted, and data of the monitor register MR is transferred to the RAM 22. When data with one or more words is accumulated in the FIFO 24, the DMA transfer in one word unit is restarted. COPYRIGHT: (C)2005,JPO&NCIPI
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