Patent ID: 6862226
Filing Date: 2005-03-01
Classification: G11C,H01L,H03K

Abstract:
1. A method of driving a non-volatile flip-flop circuit comprising: a first inverter having an input terminal and an output terminal which are connected to a first memory node and a second memory node, respectively, a second inverter having an input terminal and an output terminal which are connected to the second memory node and the first memory node, respectively, a first pass transistor which has a gate connected to a word line and is connected between a first bit line and the first memory node, a second pass transistor which has a gate connected to the word line and is connected between a second bit line and the second memory node, a first switching element for control and a first variable resistor element which are connected serially to each other and are connected between the first memory node and a plate line, and a second switching element for control and a second variable resistor element which are serially connected to each other and are connected between the second memory node and the plate line; wherein the resistance values of the first and second variable resistor elements can be changed by the heat generated by a current; the method comprising: a STORE step and a subsequent RECALL step, the STORE step having a first step in which both the first and second variable resistor elements are made low resistive, and a second step which follows the first step, and in which while either the first or second variable resistor element, whichever is connected to the memory node storing “0”, is maintained low resistive, only the variable resistor element which is connected to the memory node storing “1” is made high resistive, and, in the RECALL step, “1” being set in the memory node which is connected to either the first or second variable resistor element, whichever is in a high resistive state, and “0” being set in the memory node which is connected to either the first or second variable resistor element, whichever is in a low resistive state.