Apparatus for transmitting signal in semiconductor integrated circuit

A signal transmitting apparatus of a semiconductor IC is provided to enhance adaptability to external conditions by controlling capability and efficiency of operation thereof. A signal transmitting apparatus of a semiconductor IC(Integrated Circuit) includes a multi level transmission control unit(10) and a signal processing unit(20). The multi level transmission control unit outputs an input signal with plural bits in series or parallel according to multi level transmission conditions. The signal processing unit selectively performs multi level transmission corresponding to a signal type delivered in series or parallel from the multi level transmission control unit.