Constants - 2023.2 English

Vivado Design Suite User Guide: Synthesis (UG901)

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2023.2 English

SystemVerilog gives three types of elaboration-time constants:

  • parameter: Is the same as the original Verilog standard and can be used in the same way.
  • localparameter: Is similar to parameter but cannot be overridden by upper-level modules.
  • specparam: Is used for specifying delay and timing values; consequently, this value is not supported in Vivado synthesis.

There is also a runtime constant declaration called const.