Abstract: A semiconductor integrated circuit that allows a self test of an integrated circuit built into a system to be conducted through a circuit structure on a smaller scale and achieves an improvement in the accuracy of the self test is provided. An integrated circuit includes functional modules respectively provided with built-in self testing circuits and a self test control circuit that individually controls the built-in self testing circuits. This structure allows self tests to be automatically performed within the integrated circuit without requiring external components. The scale of the system having the built-in integrated circuit may thus be reduced. Also, by building up the built-in self testing circuits in the individual functional modules to a sufficient degree, a high-quality self test comparable to that conducted prior to shipment can be performed even after the integrated circuit is built into the system.