A program circuit activates a pass signal when a first program unit is
programmed. The first program unit is programmed when a test of an
internal circuit is passed. A mode setting circuit switches an operation
mode to a normal operation mode or a test mode by external control. A
state machine allows a partial circuit of the internal circuit to perform
an unusual operation different from a normal operation when the pass
signal is inactivated during the normal operation mode. By recognizing
the unusual operation during the normal operation mode, it can be easily
recognized that a semiconductor integrated circuit is bad. Since a
failure can be recognized without shifting to the test mode, for example,
a user who purchases the semiconductor integrated circuit can also easily
recognize the failure.