Realizing small-footprint and energy-efficient optical switching fabrics is of crucial importance to solve the data movement challenges faced by optical interconnection networks. This letter demonstrates silicon photonic $2\times 2$ full crossbar switching functionality based on a single microring. The ultra-compact device is shown to successfully switch data channels from two input ports simultaneously. Data channels in both the multiple and the same wavelength switching experiments are measured to be error-free. Simulation shows that by optimizing some of the microring parameters crosstalk could be reduced. This letter confirms the applicability of a single microring as a $2\times 2$ switch element for on-chip optical interconnects.