Patent ID: 6788567
Filing Date: 2004-09-07
Classification: G11C

Abstract:
A data holding device comprising:a data holding circuit in which data are held by connecting first and second inverter circuits in a loop at the time of latching data; and a nonvolatile memory element which records a nonvolatile state corresponding to data existing in said data holding circuit with one end of the nonvolatile memory element connected to an input node of said first inverter circuit at the time of writing data, and which discharges an electric charge which corresponds to said nonvolatile state recorded in the nonvolatile memory element and which can generate a voltage higher or lower than the threshold voltage of said first inverter circuit at said input node of said first inverter circuit to said input node of said first inverter circuit when said one end is connected to said input node of said first inverter circuit and a reading signal is applied to the other end of the nonvolatile memory element at the time of restoring data, said data holding circuit having a loop switching gate which is interposed between a nonvolatile memory element connecting node defined as a connecting node between said input node of said first inverter circuit and said one end of said nonvolatile memory element, and an output node of said second inverter circuit, and which is on at the time of latching and writing data, and off in applying said reading signal and on after a lapse of a predetermined period of time at the time of restoring data.