Method of estimating self refresh period of semiconductor memory device

摘要

In a method of estimating a self refresh period of a semiconductor memory device according to an exemplary embodiment, a plurality of internal address signals are reset in response to a refresh reset signal. The plurality of internal address signals are sequentially changed synchronously with an oscillation signal. A refresh completion signal is generated based on the plurality of internal address signals. The self refresh period is detected based on the refresh reset signal and the refresh completion signal.