A memory package includes; a first memory chip including first memory pads, and a buffer chip including first buffer pads respectively connected with the first memory pads and second buffer pads connected with an external device. The buffer chip respectively communicates signals received via the second buffer pads to the first buffer pads in response to a swap enable signal having a disabled state, and the buffer chip swaps signals received via the second buffer pads to generate first swapped signals, and respectively communicates the first swapped signals to the first buffer pads in response to the swap enable signal having an enabled state.