PURPOSE: To delay an optional signal without disturbing a wave form of an internal signal and unsealing a case by controlling a driving of an addressbuffer, a delay program circuit by address signals of different thresholds.

CONSTITUTION: When an address input terminal Ai is brought to above a first threshold, an address buffer 10 is driven. When this terminal Ai is brought to above a second threshold voltage higher than the first threshold voltage, an N channel transistor Q2 of a delay program circuit is turned on through an N channel transistor Q1, and a fuse 6 is melted. Thereby, an output of a circuit passing through an inverter 1 is reversed to H and a capacitor C of a delay circuit 12 is connected and by a change of a time constant, a signal of a desired delay section N is delayed. Thus, an optional signal of a memory circuit is easily and accurately delayed without disturbing an internal signal and unsealing.