| 摘要 |
PURPOSE:To prevent an oscillation phenomenon on a data bus by setting a flip-flop FF when a memory read signal outputted from a CPU is active and then resetting the FF when the output of a gate circuit is inactive. CONSTITUTION:An FF25 is set when the memory read signal outputted from a CPU 1 is active and then reset when the output of a gate circuit 26 is inactive respectively. Therefore, the conducting direction of a bidirectional driver 15 is fixed in a read mode before the output control signal given to the driver 15. At the same time, the fixed conducting direction is kept even after the output control signal is inactive and the driver 15 is cut off. Thus the driver 15 conducts only in the direction where the driver 15 moves toward the CPU 1 from a peripheral circuit in the read mode. As a result, an oscillation phenome non is prevented on a data bus 7.
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