A DRAM includes: a temperature sensor for monitoring a temperature operating condition of the DRAM; and a binary counter coupled to the temperature sensor, for receiving external commands to perform a refresh operation, and incrementing a count upon each received external command, wherein the refresh operation will be selectively skipped according to a value of the binary counter. The binary counter is activated to a first mode when the temperature sensor determines the temperature operating condition of the DRAM goes below a first threshold and activated to a second mode when the temperature sensor determines the temperature operating condition of the DRAM goes below a second threshold lower than the first threshold.