Global Variables on the Interface - 2023.2 English

Vitis High-Level Synthesis User Guide (UG1399)

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2023.2 English

Both Vivado HLS and AMD Vitis™ HLS allow global variables to be freely used in the code and are fully synthesizable. However, while Vivado HLS supported exporting global variables in the top-level function interface, AMD Vitis™ HLS does not.

Global variables can not be used as arguments to the top-level function, or exposed as ports on the RTL interface in AMD Vitis™ HLS. Variables needed on the interface of the top-level function must be explicitly declared in the interface.