SEMICONDUCTOR MEMORY

摘要

PURPOSE:To measure the speed of a main memory cell while suppressing the error by measuring the speed of the submemory cell in an OTPROM. CONSTITUTION:The semiconductor memory comprises a main memory cell 114 for storing data, a dummy decoder 112 for selecting a submemory cell 115, and a dummy decoder selection mode setting circuit 118 producing a mode signal for activating the dummy decoder 112 based on an external signal. The circuit 18 is provided with a mode control circuit 108 for preventing variation of the output signal due to the state of an external signal for setting the operating/nonoperating state of the semiconductor memory including the circuit 18 after provision of a mode signal for activating the dummy decoder 112 in order to measure the speed of delay time TCE of the submemory cell.