SEMICONDUCTOR MEMORY, IN WHICH REFRESH OPERATION IS PERFORMED PRECISELY

摘要

PURPOSE: A semiconductor memory is provided to evaluate the inside of a chip to perform a refresh operation accurately, and thus to reduce a test cost by simplifying an actual value of an access cycle when an access operation competes with the refresh operation. CONSTITUTION: A memory core(36) has a plurality of memory cells, a bit line connected to the memory cells and a sense amplifier connected to the bit line. A command control circuit outputs an access control signal to access the memory cell in response to an access request supplied through a command port. A refresh timer(16) generates an internal refresh request. A relay circuit(28) outputs a refresh control signal and an access control signal according to a priority of the access operation and the refresh operation. A row operation control circuit(32) performs the access operation as to the memory core in response to the access control signal, and performs the refresh operation as to the memory core in response to the refresh control signal. And a detection circuit outputs a detection signal indicating that the refresh operation is not performed, when there is a new internal refresh request before the refresh operation corresponding to the internal refresh request is not performed.