Methods for row hammer mitigation and memory devices and systems employing the same

A method of operating a memory device is provided, comprising determining a number of operations corresponding to a memory location during a first timing period; and scheduling an extra refresh operation for the memory location after the first timing period when the determined number of operations exceeds a predetermined threshold. A memory device is provided, comprising a memory including a memory location; and circuitry configured to: determine a number of operations corresponding to the memory location during a first timing period; and schedule an extra refresh operation for the memory location after the first timing period when the determined number of operations exceeds a predetermined threshold.