// DESCRIPTION: Verilator: Verilog Test module // // This program is free software; you can redistribute it and/or modify it // under the terms of either the GNU Lesser General Public License Version 3 // or the Perl Artistic License Version 2.0. // SPDX-FileCopyrightText: 2022 Geza Lore // SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0 module top ( input clk ); reg clk_half = 0; reg [31:0] cyc = 0; reg [31:0] a, b, c; always @(posedge clk) begin $display("tick %d: a: %d, b: %d, c: %d", cyc, a, b, c); // Check invariant if (cyc + 1 !== a) $stop; if (cyc + 2 !== b) $stop; if (cyc + 2 !== c) $stop; // End of test if (cyc == 100) begin $write("*-* All Finished *-*\n"); $finish; end cyc <= cyc + 1; end always @(posedge clk) a = cyc + $c(1); always @(a) b = a + $c(1); assign c = a + $c(1); endmodule