| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the number of busy signal lines by providing each busy control circuit, and using both a data signal which operates in almost the same way as the busy signal and a data transmission line. SOLUTION: A busy signal BY is outputted from a busy control circuit 12 of a device A1 to data DA outputted from a data transmitting circuit 13, and the output of the data DA is communicated to a device B2. The device B2 confirms the busy signal BY in the data signal DA, outputs a busy signal BZ for communicating the possibility of the output of a clock CK from a busy control circuit 22 as data DB, and transmits it to the device A1. In the device A1, a clock generating circuit 11 outputs the clock CK, and the data transmits circuit 13 outputs the data DA. In the device B2, a data receiving circuit 24 receives the data DA synchronously with the clock CK. The device A1 sets the clock generating circuit 11 in an input state, and outputs a busy signal BY for releasing busy. Also, the device B2 outputs the busy signal BZ for releasing busy.</p> |
