[Turn] overshoot, ringing, non-monotonic

Overshoot (overshoot)

Overshoot is often generated when a faster signal is driven along a longer line and there is no valid match on the route.     The problem caused by overshoot is that the signal high level "1" exceeds the input maximum voltage value of the receiving device, or the signal low level "0" is lower than the input minimum voltage value of the receiving device. The general way to deal with overshoot is to match, or call to end (termination). Termination can be summed up in two forms: The remote series matching eliminates two reflections, and the terminal parallel matching eliminates the one-time reflection. Note Not every method is suitable for any occasion.     For example 50ohm parallel matching is generally not applicable with Lvttl/lvcmos level logic, because the power consumption of the resistor is very large. Another way to reduce overshoot is to reduce the drive current on the drive side. Ringing (ring) overshoot is often accompanied by ringing, or the punch is part of the ringing.     The first peak voltage generated by ringing is overshoot. In addition to the impact of ringing, the voltage fluctuations generated may cross the threshold voltage of the logic level multiple times, resulting in a false receiver. For COMs devices, ringing can cause the upper and lower MOS tubes to have a long lead time and increase the device power consumption dramatically. Non-monotonic (non monotonic) Most non-monotonic is caused by complex signal topologies. Non-monotonic problems are most common on a single CPU or DSP local bus.     Non-monotonic can be divided into two types according to the form of expression: the back hook and the step. For a valid clock, the back hooks and steps on the signal edge are deadly. Because of a non-monotonic clock edge, it may be recognized by the receiver as multiple effective along, or within the device to produce a metastable state, resulting in a functional error of the timing logic. For the data, the non-monotonic harm is mainly caused by the reduction of the time margin, which is one of the reasons why complex bus systems often need timing simulation. Original address: http://www.cnblogs.com/chenman/p/3649343.html

[Turn] overshoot, ringing, non-monotonic