Method and apparatus for providing a protection circuit for protecting an
integrated circuit design is described. In one example, a sequence
generator is defined to produce a pseudorandom sequence of output
vectors. A plurality of output vectors is selected from the sequence of
output vectors. Bits from the plurality of output vectors are randomly
selected to define a terminal vector. Detection logic is generated for
detecting the terminal vector. In another example, a protection circuit
is defined for asserting a signal after a plurality of clock cycles. At
least one lookup table (LUT) is identified in the implemented circuit
design having at least one unused input terminal. The signal is coupled
to the at least one unused input terminal of the at least one LUT. The
protection circuit and the circuit design are then implemented.