REDUNDANCY CIRCUIT FOR SEMICONDUCTOR MEMORY DEVICE AND ITS REDUNDANCY DECODER

摘要

PROBLEM TO BE SOLVED: To provide a redundant circuit which can quickly select a redundant word line in a synchronizing type semiconductor memory. SOLUTION: This device is provided with an address buffer 14 outputting a redundant address RAi making an input address XAi synchronized with a first synchronizing signal KFRST, a redundant decoder 15 having a program means programming an address ands actively outputting a redundant decoding signal RPi synchronizing with a second synchronizing signal KFRST 2 when the programmed address coincides with the redundant address RAi, and a redundant word line decoder 16 selecting a redundant work line in accordance with the redundant decoding signal RPi. As the signal RPi is synchronized with the synchronized signal KFRST 2, a delay time of the redundant decoder can be shortened without considering active and non-active margin of the signal RPi.