| 摘要 |
PURPOSE:To avoid a failure current from an output terminal and to protect the output terminal from being dstroyed, by making the terminal to a high impedance, when the output terminal is short-circuited to other potentials. CONSTITUTION:When an output terminal is not short-circuited to other potential, since the output of a latch and of the terminal are in phase, an EX-NOR6 in a coincidence circuit goes to ''H''. Thus, even if a latch clock is lost and the potential is low, an NOR5 having a high impedance signal remains ''L'' and the output of the latch is outputted as it is at the terminal. If the terminal is short- circuited with other outputs and the potential is in opposite phase to data desired to be outputted, the NOR6 of the coincidence circuit outputs ''L''. When the latch lock is L, the NOR5 outputs ''H'' and the terminal goes to a high impedance state. |
