SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE

PURPOSE:To increase oscillation force while maintaining high speed properties of an electric current by making a length between an idle pad corresponding to an I/O cell at a branch side and a ground line to which the ground side of each I/O cell is connected short and making idle pad potential act as ground potential. CONSTITUTION:When more than two I/O cells 2 are connected in parallel to a piece of external pad 1a, an idle pad 11a corresponding to an I/O cell 2a at a branch side and a ground line 6 to which the ground side of each I/O cell 2 is connected are connected so as to make the length between them short and potential of the idle pad 11a is made to act as ground potential. As a result, even though an electric current increases a driving force while maintaining its high speed properties, the steep current from unified I/O cells 2 and 2a flows directly to ground potential through the pad 11a corresponding to the I/O cell 2a at the branch side and its configuration makes ground impedance low.