EE382C Embedded Software Systems - Boolean Dataflow

Boolean Dataflow

• Actors are allowed to have one Boolean control port which may control inputs and output ports. All other ports obey Synchronous Dataflow semantics.
• Switch (demultiplexing) actor: the input token is put on either the True output port or the False output port according to the value of the token on the control port.
• Select (multiplexing) actor: the output token is the token on either the True input port or False output port according to the value of the token on the control port.
• The Boolean control port is read first and then the appropriate input port is read
• Switch and select can be used to data-dependent iteration (e.g., while statements and for loops)
• Allows conditional flow of data
• Heuristics can often cluster the Boolean Dataflow graph into a cluster whose input/output behavior obeys Synchronous Dataflow semantics. To the actors outside the cluster, the cluster obeys Synchronous dataflow semantics. Unclustered actors are dynamically scheduled, and the clusters are statically scheduled. This is an example of quasi-static scheduling.