A semiconductor memory chip includes an upper data pad region, a lower data pad region, and an additional pad region. Upper data pads, upper data strobe signal pair pads, and an upper data mask signal pad are arranged in the upper data pad region. Lower data pads, lower data strobe signal pair pads, and a lower data mask signal pad are arranged in the lower data pad region adjacent to and below the upper data pad region. An inverted termination data strobe signal pad used for a second semiconductor memory package and internally connected to the upper data mask signal pad, which is used for a first semiconductor memory package, is arranged in the additional pad region adjacent to and above the upper data pad region.