Nonvolatile memory device using variable resistive element and memory system having the same

摘要

A nonvolatile memory device, which has an improved read reliability through a refresh operation, and a memory system, are provided. The nonvolatile memory device includes a resistive memory cell, a reference resistor corresponding to the resistive memory cell, a reference sense amplifier electrically connected to the reference resistor and configured to change a transition time of an output value of the reference resistor, and a refresh request signal generator configured to output the refresh request signal for the resistive memory cell when the transition time of an output value of the reference resistor is in a preset refresh requiring period.

主权项

1. A nonvolatile memory device comprising:
a resistive memory cell; a reference resistor corresponding to the resistive memory cell; a reference sense amplifier electrically connected to the reference resistor and configured to generate a reference output signal based on the reference resistor; and a refresh request signal generator configured to output a refresh request signal for the resistive memory cell responsive to the reference output signal and a refresh period mask signal, the refresh period mask signal being indicative of a time period in which the resistive memory cell is in need of refresh.