VERILOG2000: Unused variables should be removed

Summary

Reliability	Security	Maintainability	Code attribute	Effort to fix	Tags

MEDIUM	-	-	Intentionality \| Logical	10min	synthesis, vscode, linter, simulation, dead-code

Description

A variable that is never used should be removed.

Noncompliant code example

module fly(input clk, output reg x);
  logic a = '0;

  int b; // Noncompliant: 'b' is never set nor read

  int c; // Noncompliant: 'c' is set but never read
  initial c = 42;

  always @(posedge clk)
  begin
    x <= a;
  end
endmodule

Compliant solution

module fly(input clk, output reg x);
  logic a = '0;

  always @(posedge clk)
  begin
    x <= a;
  end
endmodule

Parameters

No parameters.