| 摘要 |
PROBLEM TO BE SOLVED: To provide a data communication system capable of continuing transfer even when one transfer route between a buffer memory and a main memory, etc., in a device becomes unavailable in data communication between devices. SOLUTION: In the data communication system which performs the data communication, for example, between a printer and other device, it is constituted by providing a printer main memory 3, buffer memories 13, 14, 15 for temporarily storing communication data in the printer, and providing a DMA (direct memory access) interface 17 and a PIO interface 18 between the buffer memories 13, 14, 15 and the printer main memory 3, and constituted so that the DMA interface 17 is normally used and the interface is switched to the PIO interface 18 when the DMA interface 17 becomes unavailable. COPYRIGHT: (C)2004,JPO
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