SWITCHING CIRCUIT FOR LOCKING WRITE ENABLE SIGNAL

摘要

PURPOSE: A switching circuit for locking a write enable ignal is used not only in a circuit having XX4 input/output terminal but also in a circuit having an X1 input/output terminal without additional mask, bonding option. CONSTITUTION: A switching circuit for locking a write enable signal comprises a lock signal generator(10) for even bits and a lock signal generator(20) for odd bits. The lock signal generator(10) for even bits logic combines with data output enable signal and column address strobe signal and row address strobe signal. And it(10) generates a lock signal for intercepting an input routine of an input terminal of an over 4bits input/output device only while reading the data. The lock signal generator(20) for odd bits transmits selectively a lock signal of 1bit input/output device according to a level of the row address strobe signal and an output of the lock signal generator(10) for even bits responding to a control command signal for a combined use of the 1bit input/output device and the data output enable signal.