IEEE 181:2011 pdf free download – IEEE Standard for Transitions, Pulses,and Related Waveforms
NOTE 1—Unless otherwise specified, multiple states are ordered from the most negative level to the most positive level,and the state levels are not allowed to overlap. The most negative state is called state 1.The most positive state is calledstate n. The states are denoted by s ,52… ; the state levels are denoted by level(s), level(sz). .., level(s,); the upperstate boundaries are denoted by upper(s), upper(S). …， upper(s.); and the lower state boundaries are denoted bylower(sg), lower(s2), .- ..lower(s,).
NOTE 2—States, levels, and state boundaries are defined to accommodate pulse metrology and digital applications. Inpulse metrology, the levels of a waveform are measured and states (with or without associated state boundaries) are thenassociated with those levels. In digital applications, states are defined (with state boundaries) and the waveform valuesare determined to either lie within a state or not.
state, base: The state of a waveform that, unless otherwise specified, possesses a level closest to zero.NOTE—See Figure 2 through Figure 6.
state, high: The most positive state within the waveform epoch, unless otherwise specified.
NOTE—For waveforms with exactly two states, such as the single transition waveform, the terms low state and highstate may be used in lieu of the terms siate 1 and state 2, respectively.
state, low: The most negative state within the waveform epoch, unless otherwise specified.
NOTE—For waveforms with exactly two states, such as the single transition waveform, the terms low state and highstate may be used in lieu of the terms siate l and state 2, respectively.
state, positive (negative): A state whose level is greater (less) than zero.
state boundaries: The upper and lower limits of the states of a waveform.All values of a waveform that arewithin the boundaries of a given stale are said to be in that state.
NOTE—The state boundaries are defined by the user.
state occurrence: A contiguous region of a waveform that is bounded by the upper and lower stateboundaries of a state, and whose duration equals or exceeds the specified minimum duration for stateattainment.
NOTE—The state occurrence consists of the entire portion of the waveform that remains within the boundaries of thatstate. State occurrences are numbered as ordered pairs (s, n), where s, refers to the ith state, and n is the number of theoccurrence of that particular state within the waveform epoch. In a given waveform epoch,when the waveform firstenters a state,s , that state occurrence is (s),1). If and when the waveform exits that state, that state ocurrence is over.lf and when the waveform next enters and remains in state sj , that state occurrence would be labcled (s), 2); and so on.Thus, the state occurrences for a single pulse (see Figure 4 and Figure 6) are (s), 1),(s,1),(Ss),2). The state occurrencesfor the compound waveform (see Figure 6) are (sz, i).(sa， 1), (s3，1),(s 1),(s)，1).Note that a waveform can exit onestate occurrence without (necessarily) immediately entering another state occurrence.That is, the waveform statebetween state occurrences can be undefined for some time interval, for example, during transitions and in the case oftransients (such as,runt pulses).
synchronizing: The process of aligning the transition occurrence instant of one pulse or other event withthe transition occurrence instant of another pulse or event. If two series of events,such as two pulse trains,are synchronized, then their periods shall be integer multiples of one another.
terminal feature: Any contiguous region of a waveform that is neither a state occurrence, nor a transient,nor a transition.This feature, if present, occurs only at the beginning andor end of a waveform.
tilt: A distortion of a waveform state wherein the overall slope over the extent of the waveform state isessentially constant and other than zero.This distortion may be of either polarity.
NOTE—The term droop is deprecated because it implies a negative slope and therefore cannot be appliedunambiguously to both positive pulse waveforms and negative pulse wavefovrms.