Semiconductor device comprising transition detecting circuit and method of activating the same

A semiconductor device comprising:

• an internal power supply which outputs an initialization completion signal when the power supply is initialized;
• at least one semiconductor circuit block which operates on the basis of a voltage generated by the internal power supply;
• a delay circuit which delays the initialization completion signal;
• and
• a detecting circuit which commands the semiconductor circuit block to start operations in response to the initialization completion signal delayed by the delay circuit and an externally input first input signal,
• wherein the detecting circuit comprises a logic circuit which performs a logical operation on the first input signal and the initialization completion signal delayed by the delay circuit, and
• a control circuit which commands the semiconductor circuit block to start operations upon detecting a transition in at least one of the result of the logical operation performed by the logic circuit and an externally input second input signal.