Circuit and method for preserving data in sleep mode of semiconductor device using test scan chain

Abstract

A data storage circuit and a data preservation method for preserving data when a semiconductor device is in a sleep mode using a test scan chain are provided, where the data storage circuit includes a sleep mode control unit and a scan chain unit, the sleep mode control unit outputs a scan control signal and a scan clock signal in response to one of a test control signal and a sleep mode control signal received from the outside, stores an output data signal in a memory when the output data signal is received, and outputs a test pattern data signal as a scan data signal when the test pattern data signal is received, the scan chain unit outputs a normal data signal stored inside of the scan chain unit as the output data signal to the sleep mode control unit or receives and outputs the scan data signal to a combinational circuit unit in response to the scan control signal and the scan clock signal, and the data storage circuit and the data preservation method prevent a loss of data in a sleep mode of a semiconductor device, and reduce power consumption in a standby state.