Overshoot and Undershoot spec in datasheet

Question: What are the overshoot and undershoot specs of Async SRAM's



"Data bus input over/under shoot pulse voltage and width" In datasheet of devices says that the ViL (min) of the part is -2.0v for pulse durations of less than 20ns which is the undershoot. The part can usually withstand an overshoot voltage of Vcc + 0.5V ( Check actual values with datasheet). The duration of the overshoot does not matter as long as the overshoot is within the specified voltage range and hence we currently do not specify the duration. The part will function irrespective of the duration of the overshoot if it is within the specified max input voltage range.