| 摘要 |
PURPOSE:To improve a responsiveness of a work station and a transfer efficiency by providing a direct memory access controlling circuits and two sets of serial/parallel converters and parallel/serial converters, etc. CONSTITUTION:In case a data transfer request is received from a work station A, a work station controlling circuit 9 detects this data transfer request by polling. Subsequently, the circuit 9 switches a selector 12 of a transferring circuit 5, connects a driver DV and a receiver RV of a port 13 to a P/S converter 3 and an S/P converter 4, respectively, and delivers a control of the circuit 13 to a direct memory access controlling circuit DMA10. As a result, the circuit 10 tranfers a data to the device A. At the same time, the circuit 9 executes the polling to work stations D-F. In this way, the polling to other work station can be executed, executing a data transfer to a specified work station, therefore, a responsiveness of the work station and a transfer efficiency can be improved. |
