A semiconductor integrated circuit includes a reference voltage generating block, a circuit block, and a transmission line. The reference voltage generating block generates a first reference voltage and generates and outputs a digital code corresponding to the level of the first reference voltage. The circuit block converts the digital code into a second reference voltage and uses the second reference voltage for operation related to the function of the semiconductor integrated circuit. The transmission line is connected between the reference voltage generating block and the circuit block to allow transmission of the digital code to the circuit block.