verilator/test_regress/t/t_assert_disable_iff.v

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed into the Public Domain, for any use,
// without warranty, 2019 by Peter Monsson.
// SPDX-License-Identifier: CC0-1.0

module t (/*AUTOARG*/
   // Inputs
   clk
   );

   input clk;
   int cyc;

   Test test (/*AUTOINST*/
              // Inputs
              .clk                      (clk));

   always @(posedge clk) begin
      cyc <= cyc + 1;
      if (cyc == 10) begin
         $write("*-* All Finished *-*\n");
         $finish;
      end
   end

endmodule

module Test (
    input clk
);

`ifdef FAIL_ASSERT_1
   assert property (@(posedge clk) disable iff (0) 0)
   else $display("wrong disable");
`endif

   assert property (@(posedge clk) disable iff (1) 0);

   assert property (@(posedge clk) disable iff (1) 1);

   assert property (@(posedge clk) disable iff (0) 1);

   //
   // Cover properties behave differently
   //

   cover property (@(posedge clk) disable iff (1) 1) $stop;

   cover property (@(posedge clk) disable iff (1) 0) $stop;

   cover property (@(posedge clk) disable iff (0) 1) $display("*COVER: ok");

   cover property (@(posedge clk) disable iff (0) 0) $stop;

endmodule