Memory system supporting a input/output path swap

PURPOSE: A memory system supporting I/O path swap is provided to increase the line efficiency of a PCB by routing a memory device through I/O path swap. CONSTITUTION: An internal circuit(1120) generates first and second chip enable signals which controls the access to first and second memory devices. An I/O(Input/Output) pad(1130) is connected to first and second I/O terminals. A I/O path swapping unit(1110) swaps an internal I/O path in response to the second chip enable signal. The I/O path swapping unit responds to the first and second chip enable signals and includes a swap control circuit(1112) and a selection circuit(1113).