To prevent the noise of the core circuit from being propagated to the input circuit or the output circuit, and to reduce noises to be generated when a repeated cyclic signal such as a clock signal is transmitted from the input circuit to the core circuit, or from the core circuit to the output circuit in a semiconductor package equipped with a core circuit, an input circuit and an output circuit .

A core circuit block is separated from any power source other than that of a core circuit so that the noise of the core circuit can be prevented from being transmitted to any other circuit block, especially, an output circuit, and ground is not completely separated inside a semiconductor, and a ground pattern is arranged in the neighborhood of signal wiring for transmitting a repeated cyclic signal being the factor of the generation of another radiation noise. The position and width of the ground pattern are specified so that the sum of noises to be generated due to the two factors can be minimized.