Patent ID: 8018757

Claim:
A semiconductor memory device comprising: a memory cell including a flip-flop including a first inverter and a second inverter connected to each other in a cross-coupling manner, the first inverter including first and second transistors connected to each other so that their current paths are serially connected, the second inverter including third and fourth transistors connected to each other so that their current paths are serially connected; a first power supply terminal connected to a source electrode of the first transistor and a source electrode of the third transistor, and supplied with a first potential in a normal operation; a second power supply terminal connected to a source electrode of the second transistor and a source electrode of the fourth transistor, and supplied with a second potential in a normal operation; and a control circuit operative to control a voltage applied to the first power supply terminal and the second power supply terminal, the control circuit being configured to perform control such that when offset information of the memory cell is to be read, a voltage applied to the first power supply terminal and a voltage applied to the second power supply terminal are made equal, then the voltage applied to the first power supply terminal is returned to the first potential, and the voltage applied to the second power supply terminal is returned to the second potential, whereas when stress is generated in the first to fourth transistor included in the first inverter or the second inverter, the potential difference between the first power supply terminal and the second power supply terminal is made larger than a difference between the first potential and the second potential.