- Enclosing class:
- Topology
protected static class Topology.CellAggregateSignal
extends java.lang.Object
Class to describe an aggregate signal (a bus) in a Cell.
The difference between aggregate signals and busses is that aggregate signals
are more sensitive to variations. For example, a bus may be X[1,2,4,5] but
there may be two aggregate signals describing it because of the noncontinuity
of the indices (thus, the aggregate signals will be X[1:2] and X_1[4:5]).
Some netlisters allow for gaps, in which case they will be described with a
single aggregate signal. Other factors that cause busses to be broken into
multiple aggregate signals are:
(1) differences in port direction (mixes of input and output, for example)
(2) differences in port type (power, ground, global, etc.)