a semiconductor integrated circuit provided with an - bit output mode and an n - bit output mode and including a set of i / o portions 103 for outputting signals to the outside , wherein data with a bus width of bits are selected by a set of selectors 101 in the - bit output mode so that the data with the bus width of bits are outputted from the set of i / o portions 103 whereas data with a bus width of n bits are multiply selected by the set of selectors 101 in the n - bit output mode so that the data with the bus width of n bits are outputted from the set of i / o portions 103 while multiplexed in at least two i / o portions per bit . every i / o portions which output one and the same bit are short - circuited externally to improve current drive capacity .