The Discrete Time (DT) domain is a timed extension of the Synchronous Dataflow (SDF) domain. Like SDF, it has static scheduling of the dataflow graph model. Likewise, DT requires that the rates on the ports of all actors be known beforehand and fixed. DT handles feedback systems in the same way that SDF does, but with additional constraints on initial tokens.
Because of the inherent concurrency occurring within SDF dataflow graph models, there are two notions of time in DT -- global time and local time. Global time increases steadily as execution progresses. Moreover, global time increments by fixed discrete chunks of time based on the value of the period parameter. On the other hand, local time applies to each of the actors in the model. All the actors have distinct local times as an iteration proceeds. The local time of an actor during an iteration depends on the global time, period, firing count, port rates, and the schedule. These local times obey the following constraint:
The exact way that local time increments during an iteration is described in detail in the DTReceiver documentation.
The DT domain is an experimental domain, the code has not been reviewed, and the interfaces are likely to change.
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