Abstract: A device and method for characterizing signal skew between a first signal and a second signal. The device includes a delay chain and a first transition detector in communication with the delay chain. The first transition detector is configured for receiving the first signal and provides a pulse signal to the delay chain upon detecting a transition of the first signal. The device includes a second transition detector which is in communication with a latch and is configured for receiving the second signal. The second transition detector sets the latch upon detecting a transition of the second signal. At least one pass gate is connected to the delay chain and the latch. At least one timing latch is connected to the pass gate for receiving signal skew information between the first and second signals.

Abstract: In an electronic IC package, an I/O PAD circuit design which protects 3 Volt optimized I/O functional circuits from damage due to the application of external 5 Volt signals to the I/O PAD both while the functional circuit design is powered on and powered off. When the I/O circuits associated with the I/O PAD are powered on, the present invention protects the I/O circuits by applying well known designs. However, when the I/O circuits associated with the I/O PAD are powered off, the present invention draws power from the external 5 Volt signal to activate additional transistors to protect the powered off I/O circuits.