An interface of integrated circuit (IC) die includes a plurality of the contact elements formed as a contact element pattern corresponding to a parallel bus. The contact elements are arranged in an array of rows and columns and divided into a transmitting group and a receiving group. The contact elements of the transmitting group have a first contact element sequence and the contact elements of the receiving group have a second contact element sequence, the first contact element sequence is identical to the second contact element sequence. The contact elements with the first contact element sequence and the second contact element sequence are matched when the contact element pattern is geometrically rotated by 180° with respect to a row direction and a column direction.