1. An integrated circuit comprising: A. functional input and output signal leads; B. input and output circuits connected to the functional input and output signal leads; C. core circuitry; D. interconnect wires and circuits connecting the input and output circuits and the core circuitry; E. an addressable test port for each core circuitry, connected to each core circuitry and to the interconnect wires and circuits; and F. external test signal leads connected to each test port.