The 4T2R cell comprises a write transistor, a first variable resistive element, a first transistor, a second variable resistive element, a second transistor, and a charge control transistor. The first transistor is electrically coupled to the first variable resistive element in series, and the second transistor is electrically coupled to the second variable resistive element in series, for providing search paths. For operating in a search phase, a pulse voltage is applied across the gate electrode and the source electrode of the first transistor (or across the gate electrode and the source electrode of the second transistor) for determining whether the gate voltage of the charge control transistor changes larger than a match threshold during the period of the pulse. Different RC-delay of the variable resistive elements controlling the voltage change speed of the gate voltage of the charge control transistor determines the matching result. |