| 摘要 |
PROBLEM TO BE SOLVED: To lighten the load on a master device by switching a chip select (CS) signal through hardware in a communication system such that the master device connected to a plurality of slave devices is configured to communicate with the respective slave devices by switching the output destination of the CS signal. SOLUTION: A counter 44 counts the number of transmission data from the master device to the slave devices and when its counted value reaches the number of transmission data previously stored for the slave device in communication, a comparing circuit C1 outputs a high signal. Further, a counter 54 counts the number of reception data from the slave device to the master device and when its counted value reaches the number of reception data previously stored for the slave device in communication, a comparing circuit C2 outputs a high signal. When the high signals are both output, a CS selecting circuit 60 automatically switches its internal connection to hold the CS signal to a salve device to communicate with next to an active level. COPYRIGHT: (C)2008,JPO&INPIT
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