Semiconductor memory device having forced fail function of forcing a memory cell at a specific address to fail and method for testing same

摘要

A semiconductor memory device is provided which has a unit by which a fail bit map can be checked instantaneously over the entire address space. The semiconductor memory device is provided with a data logic forcefully controlling circuit 21 which forcefully controls the logic of write data into memory cells selected by using a specified address signal or of read data, a specified row forcefully controlling circuit 40 which forcefully makes the control of memory cells selected according to specified row addresses the control exercised during operation different from normal operation, or a specified column forcefully controlling circuit 50 which forcefully makes the control of memory cells selected according to specified column addresses the control exercised during operation different from normal operation. This forced fail operation mode is selectable aside from normal operation mode.