shows the methodology to determine the overshoot duration. The overshoot voltage is shown in red and is present on the input pin of the Cyclone IV device at over 4.3 V but below 4.4 V. From , for an overshoot of 4.3 V, the percentage of high time for the overshoot can be as high as 65% over a 10-year period. Percentage of high time is calculated as ([delta T]/T) × 100. This 10-year period assumes that the device is always turned on with 100% I/O toggle rate and 50% duty cycle signal. For lower I/O toggle rates and situations in which the device is in an idle state, lifetimes are increased.
