SEMICONDUCTOR MEMORY DEVICE

摘要

PROBLEM TO BE SOLVED: To test a spare element even after being packaged by setting a test mode and forcibly activating at least one of a redundant row and a redundant column. SOLUTION: When a spare element is tested (low), a combination of external addresses is set to a redundant row test mode among a spare element test mode. Thereafter, an input command is set to a mode register set cycle. An output of a mode register (1) 43 consequently changes from a 'LOW' level to a 'HIGH' level. Then, the input command becomes row active. At the same time, an output of a control circuit 41 changes from the 'LOW' level to the 'HIGH' level. A redundant row activation circuit 24 forcibly activates a redundant row. According to the mode, those connected to normal bit liens can be tested among the redundant row.