Control and Data Driven Tasks - 2023.2 English

Vitis High-Level Synthesis User Guide (UG1399)

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2023.2 English

Using this abstract model as the basis, two types of task-level parallelism (TLP) models can be used to structure and design your application. TLP can be data-driven or control-driven, or can mix control-driven and data-driven tasks in a single design. The main differences between these two models are:

  • If your application is purely data-driven, does not require any interaction with external memory and the functions can execute in parallel with no data dependencies, then the data-driven TLP model is the best fit. You can design a purely data-driven model that is always running, requires no control, and reacts only to data. For additional details refer to Data-driven Task-level Parallelism.
  • If your application requires some interaction with external memory, and there are data dependencies between the tasks that execute in parallel, then the control-driven TLP model is the best fit. Vitis HLS infers the parallelism between tasks and creates the right channels (as defined by you) such that these functions can be overlapped during execution. The control-driven TLP model is also known as the dataflow optimization in Vitis HLS as described in Control-driven Task-level Parallelism.

The next few sections describe these major modeling options that are available to use. You can use any of these models to write your source code using C++ to optimize the execution of the program on parallel hardware.