| 摘要 |
<p>PURPOSE:To make the adding of a buffer unnecessary when microcomputers more than two are connected by providing a buffer circuit between peripheral circuits and an input/output terminal and controlling the continuity of the buffer circuit corresponding to an external signal. CONSTITUTION:An incorporated peripheral 104 connected by a CPU block 102 and an internal bus 103 of a microcomputer 101 is inputted to a buffer 110. Then, an HZRQ signal 106 is inputted to a high impedance control part 109. Then, the high impedance control part 109 outputs a RQ signal to the buffer 110 and a BIU 111, makes the buffer 110 and the BIU be in a off condition and makes an input/output terminal be in a high impedance condition. Thus, even when the microcomputers more than two are connected to the bus of one system, it is unnecessary to put the buffer between the buses.</p> |
