The objective of the invention is to be able to switch between execution and
cancellation of copy protection at any time in a simplified structure. The switching
circuit 24 is provided within the gate array unit 16 in the signal
path between the scan-path interface circuit 18 and the terminal pin for
the emulation. The DSP 10 accesses the switching circuit 24 through
the internal bus, logic interface circuit 26, and the logic bus, and can
write the intended switch control information to the register within the switching
circuit 24. The switching circuit 24 selectively switches the signal
path between the interrupted state and the conductive state according to the switch
control information given by the DSP 10, and selectively switches the scan-path
interface circuit 18 between the enabled state and the disabled state.
