Global Variables on the Interface - 2022.2 English

Vitis High-Level Synthesis User Guide (UG1399)

Document ID
Release Date
2022.2 English

Both Vivado HLS and 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, 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 Vitis™ HLS. Variables needed on the interface of the top-level function must be explicitly declared in the interface.