Patent 7944769 was granted and assigned to Xilinx on May, 2011 by the United States Patent and Trademark Office.
A system for detecting power-on of a circuit block within an integrated circuit (IC). The system can include a latch including a latch output and an inverted latch output. The latch can be coupled to, and powered by, a power supply providing power to the circuit block within the IC. The system further can include an exclusive OR circuit. The exclusive OR circuit can include an input stage coupled to the latch output and the inverted latch output. The exclusive OR circuit generates an output signal indicating whether the circuit block is in a power-on state.