Prompt:
module top_module(
	input clk,
	input slowena,
	input reset,
	output reg [3:0] q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input slowena,
	input reset,
	output reg [3:0] q);

	always @(posedge clk)
		if (reset)
			q <= 0;
		else if (slowena) begin
			if (q == 9)
				q <= 0;
			else
				q <= q+1;
		end

endmodule

module stimulus_gen (
	input clk,
	output reg slowena,
	output reg reset,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	reg hint1;
	initial begin
		reset <= 1;
		slowena <= 1;
		wavedrom_start("Synchronous reset and counting.");
		reset_test();
		repeat(12) @(posedge clk);
		wavedrom_stop();
		@(posedge clk);

		//wavedrom_start("Testing.");
		reset <= 1;
		@(posedge clk);
		reset <= 0;
		repeat(9) @(posedge clk);
		slowena <= 0;
		@(negedge clk) hint1 = tb_match;
		repeat(3) @(posedge clk);
		if (hint1 && !tb_match) begin
			$display ("Hint: What is supposed to happen when the counter is 9 and not enabled?");
		end
		//wavedrom_stop();
		slowena <= 1;
		reset <= 1;
		@(posedge clk);
		reset <= 0;

		wavedrom_start("Enable/disable");
		repeat(15) @(posedge clk) slowena <= !($random & 1);
		wavedrom_stop();
		@(posedge clk);

		repeat(400) @(posedge clk, negedge clk) begin
			slowena <= !($random&3);
			reset <= !($random & 31);
		end
		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_q;
		int errortime_q;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic slowena;
	logic reset;
	logic [3:0] q_ref;
	logic [3:0] q_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,slowena,reset,q_ref,q_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.slowena,
		.reset );
	reference_module good1 (
		.clk,
		.slowena,
		.reset,
		.q(q_ref) );

	top_module top_module1 (
		.clk,
		.slowena,
		.reset,
		.q(q_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_q) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "q", stats1.errors_q, stats1.errortime_q);
		else $display("Hint: Output '%s' has no mismatches.", "q");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { q_ref } === ( { q_ref } ^ { q_dut } ^ { q_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (q_ref !== ( q_ref ^ q_dut ^ q_ref ))
		begin if (stats1.errors_q == 0) stats1.errortime_q = $time;
			stats1.errors_q = stats1.errors_q+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input d,
	output reg q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input d,
	output reg q);

	initial
		q = 1'hx;

	always @(posedge clk)
		q <= d;

endmodule

module stimulus_gen (
	input clk,
	output reg d,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	always @(posedge clk, negedge clk)
		d <= $urandom;

	initial begin
		@(posedge clk);
		wavedrom_start("Positive-edge triggered DFF");
		repeat(10) @(posedge clk);
		wavedrom_stop();

		repeat(100) @(posedge clk, negedge clk);
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_q;
		int errortime_q;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic d;
	logic q_ref;
	logic q_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,d,q_ref,q_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.d );
	reference_module good1 (
		.clk,
		.d,
		.q(q_ref) );

	top_module top_module1 (
		.clk,
		.d,
		.q(q_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_q) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "q", stats1.errors_q, stats1.errortime_q);
		else $display("Hint: Output '%s' has no mismatches.", "q");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { q_ref } === ( { q_ref } ^ { q_dut } ^ { q_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (q_ref !== ( q_ref ^ q_dut ^ q_ref ))
		begin if (stats1.errors_q == 0) stats1.errortime_q = $time;
			stats1.errors_q = stats1.errors_q+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input d,
	output reg q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input d,
	output reg q);

	initial
		q = 1'hx;

	always @(posedge clk)
		q <= d;

endmodule

module stimulus_gen (
	input clk,
	output reg d,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	always @(posedge clk, negedge clk)
		d <= $urandom;

	initial begin
		@(posedge clk);
		wavedrom_start("Positive-edge triggered DFF");
		repeat(10) @(posedge clk);
		wavedrom_stop();

		repeat(100) @(posedge clk, negedge clk);
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_q;
		int errortime_q;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic d;
	logic q_ref;
	logic q_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,d,q_ref,q_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.d );
	reference_module good1 (
		.clk,
		.d,
		.q(q_ref) );

	top_module top_module1 (
		.clk,
		.d,
		.q(q_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_q) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "q", stats1.errors_q, stats1.errortime_q);
		else $display("Hint: Output '%s' has no mismatches.", "q");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { q_ref } === ( { q_ref } ^ { q_dut } ^ { q_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (q_ref !== ( q_ref ^ q_dut ^ q_ref ))
		begin if (stats1.errors_q == 0) stats1.errortime_q = $time;
			stats1.errors_q = stats1.errors_q+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input resetn,
	input [1:0] byteena,
	input [15:0] d,
	output reg [15:0] q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input resetn,
	input [1:0] byteena,
	input [15:0] d,
	output reg [15:0] q);

	always @(posedge clk) begin
		if (!resetn)
			q <= 0;
		else begin
			if (byteena[0])
				q[7:0] <= d[7:0];
			if (byteena[1])
				q[15:8] <= d[15:8];
		end
	end

endmodule

module stimulus_gen (
	input clk,
	output reg [15:0] d, output reg [1:0] byteena,
	output reg resetn,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);
	reg reset;
	assign resetn = ~reset;

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

	initial begin
		reset <= 1;
		byteena <= 2'b11;
		d <= 16'habcd;
		@(posedge clk);
		wavedrom_start("Synchronous active-low reset");
		reset_test(0);
		repeat(2) @(posedge clk);
		wavedrom_stop();
		@(posedge clk);

		byteena <= 2'b11;
		d <= $random;
		@(posedge clk);
		@(negedge clk);
		wavedrom_start("DFF with byte enables");
		repeat(10) @(posedge clk) begin
			d <= $random;
			byteena <= byteena + 1;
		end
		wavedrom_stop();

		repeat(400) @(posedge clk, negedge clk) begin
			byteena[0] <= ($random & 3) != 0;
			byteena[1] <= ($random & 3) != 0;
			d <= $random;
		end
		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_q;
		int errortime_q;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic resetn;
	logic [1:0] byteena;
	logic [15:0] d;
	logic [15:0] q_ref;
	logic [15:0] q_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,resetn,byteena,d,q_ref,q_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.resetn,
		.byteena,
		.d );
	reference_module good1 (
		.clk,
		.resetn,
		.byteena,
		.d,
		.q(q_ref) );

	top_module top_module1 (
		.clk,
		.resetn,
		.byteena,
		.d,
		.q(q_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_q) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "q", stats1.errors_q, stats1.errortime_q);
		else $display("Hint: Output '%s' has no mismatches.", "q");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { q_ref } === ( { q_ref } ^ { q_dut } ^ { q_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (q_ref !== ( q_ref ^ q_dut ^ q_ref ))
		begin if (stats1.errors_q == 0) stats1.errortime_q = $time;
			stats1.errors_q = stats1.errors_q+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input [7:0] d,
	input areset,
	output reg [7:0] q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input [7:0] d,
	input areset,
	output reg [7:0] q);

	always @(posedge clk, posedge areset)
		if (areset)
			q <= 0;
		else
			q <= d;

endmodule

module stimulus_gen (
	input clk,
	output reg [7:0] d, output areset,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);

	reg reset;
	assign areset = reset;

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

	initial begin
		reset <= 1;
		d <= $random;
		@(negedge clk);
		@(negedge clk);
		wavedrom_start("Asynchronous active-high reset");
		reset_test(1);
		repeat(7) @(negedge clk) d <= $random;
		@(posedge clk) reset <= 1;
		@(negedge clk) reset <= 0; d <= $random;
		repeat(2) @(negedge clk) d <= $random;
		wavedrom_stop();

		repeat(400) @(posedge clk, negedge clk) begin
			reset <= !($random & 15);
			d <= $random;
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_q;
		int errortime_q;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic [7:0] d;
	logic areset;
	logic [7:0] q_ref;
	logic [7:0] q_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,d,areset,q_ref,q_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.d,
		.areset );
	reference_module good1 (
		.clk,
		.d,
		.areset,
		.q(q_ref) );

	top_module top_module1 (
		.clk,
		.d,
		.areset,
		.q(q_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_q) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "q", stats1.errors_q, stats1.errortime_q);
		else $display("Hint: Output '%s' has no mismatches.", "q");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { q_ref } === ( { q_ref } ^ { q_dut } ^ { q_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (q_ref !== ( q_ref ^ q_dut ^ q_ref ))
		begin if (stats1.errors_q == 0) stats1.errortime_q = $time;
			stats1.errors_q = stats1.errors_q+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input enable,
	input S,
	input A,
	input B,
	input C,
	output reg Z
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input enable,
	input S,
	input A,
	input B,
	input C,
	output reg Z
);

	reg [7:0] q;
	always @(posedge clk) begin
		if (enable)
			q <= {q[6:0], S};
	end

	assign Z = q[ {A, B, C} ];

endmodule

module stimulus_gen (
	input clk,
	output logic S, enable,
	output logic A, B, C,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		enable <= 0;
		{A,B,C} <= 0;
		S <= 1'bx;
		@(negedge clk) wavedrom_start("A 3-input AND gate");
			@(posedge clk);
			@(posedge clk) enable <= 1; S <= 1;
			@(posedge clk) S <= 0;
			@(posedge clk) S <= 0;
			@(posedge clk) S <= 0;
			@(posedge clk) S <= 0;
			@(posedge clk) S <= 0;
			@(posedge clk) S <= 0;
			@(posedge clk) S <= 0;
			@(posedge clk) enable <= 0; S <= 1'bx;
			{A,B,C} <= 5;
			@(posedge clk) {A,B,C} <= 6;
			@(posedge clk) {A,B,C} <= 7;
			@(posedge clk) {A,B,C} <= 0;
			@(posedge clk) {A,B,C} <= 1;
		@(negedge clk) wavedrom_stop();

		repeat(500) @(posedge clk, negedge clk) begin
			{A,B,C,S} <= $random;
			enable <= ($random&3) == 0;
		end

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_Z;
		int errortime_Z;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic enable;
	logic S;
	logic A;
	logic B;
	logic C;
	logic Z_ref;
	logic Z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,enable,S,A,B,C,Z_ref,Z_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.enable,
		.S,
		.A,
		.B,
		.C );
	reference_module good1 (
		.clk,
		.enable,
		.S,
		.A,
		.B,
		.C,
		.Z(Z_ref) );

	top_module top_module1 (
		.clk,
		.enable,
		.S,
		.A,
		.B,
		.C,
		.Z(Z_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_Z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "Z", stats1.errors_Z, stats1.errortime_Z);
		else $display("Hint: Output '%s' has no mismatches.", "Z");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { Z_ref } === ( { Z_ref } ^ { Z_dut } ^ { Z_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (Z_ref !== ( Z_ref ^ Z_dut ^ Z_ref ))
		begin if (stats1.errors_Z == 0) stats1.errortime_Z = $time;
			stats1.errors_Z = stats1.errors_Z+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input a,
	input b,
	input c,
	input d,
	output out_sop,
	output out_pos
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input a,
	input b,
	input c,
	input d,
	output out_sop,
	output out_pos
);

	wire pos0, pos1;
	assign out_sop = c&d | ~a&~b&c;
	assign pos0 = c & (~b|d)&(~a|b);
	assign pos1 = c & (~b|d)&(~a|d);

	assign out_pos = (pos0 == pos1) ? pos0 : 1'bx;
endmodule

module stimulus_gen (
	input clk,
	output logic a, b, c, d,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	bit fail = 0;
	bit fail1 = 0;
	always @(posedge clk, negedge clk)
		if (!tb_match)
			fail = 1;

	initial begin
		@(posedge clk) {a,b,c,d} <= 0;
		@(posedge clk) {a,b,c,d} <= 1;
		@(posedge clk) {a,b,c,d} <= 2;
		@(posedge clk) {a,b,c,d} <= 4;
		@(posedge clk) {a,b,c,d} <= 5;
		@(posedge clk) {a,b,c,d} <= 6;
		@(posedge clk) {a,b,c,d} <= 7;
		@(posedge clk) {a,b,c,d} <= 9;
		@(posedge clk) {a,b,c,d} <= 10;
		@(posedge clk) {a,b,c,d} <= 13;
		@(posedge clk) {a,b,c,d} <= 14;
		@(posedge clk) {a,b,c,d} <= 15;
		@(posedge clk) fail1 = fail;

		//@(negedge clk) wavedrom_start();
			for (int i=0;i<16;i++)
				@(posedge clk)
					{a,b,c,d} <= i;
		//@(negedge clk) wavedrom_stop();

		repeat(50) @(posedge clk, negedge clk)
			{a,b,c,d} <= $random;

		if (fail && ~fail1)
			$display("Hint: Your circuit passes on the 12 required input combinations, but doesn't match the don't-care cases. Are you using minimal SOP and POS?");

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_out_sop;
		int errortime_out_sop;
		int errors_out_pos;
		int errortime_out_pos;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic a;
	logic b;
	logic c;
	logic d;
	logic out_sop_ref;
	logic out_sop_dut;
	logic out_pos_ref;
	logic out_pos_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,c,d,out_sop_ref,out_sop_dut,out_pos_ref,out_pos_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b,
		.c,
		.d );
	reference_module good1 (
		.a,
		.b,
		.c,
		.d,
		.out_sop(out_sop_ref),
		.out_pos(out_pos_ref) );

	top_module top_module1 (
		.a,
		.b,
		.c,
		.d,
		.out_sop(out_sop_dut),
		.out_pos(out_pos_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_out_sop) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out_sop", stats1.errors_out_sop, stats1.errortime_out_sop);
		else $display("Hint: Output '%s' has no mismatches.", "out_sop");
		if (stats1.errors_out_pos) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out_pos", stats1.errors_out_pos, stats1.errortime_out_pos);
		else $display("Hint: Output '%s' has no mismatches.", "out_pos");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { out_sop_ref, out_pos_ref } === ( { out_sop_ref, out_pos_ref } ^ { out_sop_dut, out_pos_dut } ^ { out_sop_ref, out_pos_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (out_sop_ref !== ( out_sop_ref ^ out_sop_dut ^ out_sop_ref ))
		begin if (stats1.errors_out_sop == 0) stats1.errortime_out_sop = $time;
			stats1.errors_out_sop = stats1.errors_out_sop+1'b1; end
		if (out_pos_ref !== ( out_pos_ref ^ out_pos_dut ^ out_pos_ref ))
		begin if (stats1.errors_out_pos == 0) stats1.errortime_out_pos = $time;
			stats1.errors_out_pos = stats1.errors_out_pos+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input a,
	input b,
	input c,
	input d,
	output out_sop,
	output out_pos
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input a,
	input b,
	input c,
	input d,
	output out_sop,
	output out_pos
);

	wire pos0, pos1;
	assign out_sop = c&d | ~a&~b&c;
	assign pos0 = c & (~b|d)&(~a|b);
	assign pos1 = c & (~b|d)&(~a|d);

	assign out_pos = (pos0 == pos1) ? pos0 : 1'bx;
endmodule

module stimulus_gen (
	input clk,
	output logic a, b, c, d,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	bit fail = 0;
	bit fail1 = 0;
	always @(posedge clk, negedge clk)
		if (!tb_match)
			fail = 1;

	initial begin
		@(posedge clk) {a,b,c,d} <= 0;
		@(posedge clk) {a,b,c,d} <= 1;
		@(posedge clk) {a,b,c,d} <= 2;
		@(posedge clk) {a,b,c,d} <= 4;
		@(posedge clk) {a,b,c,d} <= 5;
		@(posedge clk) {a,b,c,d} <= 6;
		@(posedge clk) {a,b,c,d} <= 7;
		@(posedge clk) {a,b,c,d} <= 9;
		@(posedge clk) {a,b,c,d} <= 10;
		@(posedge clk) {a,b,c,d} <= 13;
		@(posedge clk) {a,b,c,d} <= 14;
		@(posedge clk) {a,b,c,d} <= 15;
		@(posedge clk) fail1 = fail;

		//@(negedge clk) wavedrom_start();
			for (int i=0;i<16;i++)
				@(posedge clk)
					{a,b,c,d} <= i;
		//@(negedge clk) wavedrom_stop();

		repeat(50) @(posedge clk, negedge clk)
			{a,b,c,d} <= $random;

		if (fail && ~fail1)
			$display("Hint: Your circuit passes on the 12 required input combinations, but doesn't match the don't-care cases. Are you using minimal SOP and POS?");

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_out_sop;
		int errortime_out_sop;
		int errors_out_pos;
		int errortime_out_pos;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic a;
	logic b;
	logic c;
	logic d;
	logic out_sop_ref;
	logic out_sop_dut;
	logic out_pos_ref;
	logic out_pos_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,c,d,out_sop_ref,out_sop_dut,out_pos_ref,out_pos_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b,
		.c,
		.d );
	reference_module good1 (
		.a,
		.b,
		.c,
		.d,
		.out_sop(out_sop_ref),
		.out_pos(out_pos_ref) );

	top_module top_module1 (
		.a,
		.b,
		.c,
		.d,
		.out_sop(out_sop_dut),
		.out_pos(out_pos_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_out_sop) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out_sop", stats1.errors_out_sop, stats1.errortime_out_sop);
		else $display("Hint: Output '%s' has no mismatches.", "out_sop");
		if (stats1.errors_out_pos) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out_pos", stats1.errors_out_pos, stats1.errortime_out_pos);
		else $display("Hint: Output '%s' has no mismatches.", "out_pos");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { out_sop_ref, out_pos_ref } === ( { out_sop_ref, out_pos_ref } ^ { out_sop_dut, out_pos_dut } ^ { out_sop_ref, out_pos_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (out_sop_ref !== ( out_sop_ref ^ out_sop_dut ^ out_sop_ref ))
		begin if (stats1.errors_out_sop == 0) stats1.errortime_out_sop = $time;
			stats1.errors_out_sop = stats1.errors_out_sop+1'b1; end
		if (out_pos_ref !== ( out_pos_ref ^ out_pos_dut ^ out_pos_ref ))
		begin if (stats1.errors_out_pos == 0) stats1.errortime_out_pos = $time;
			stats1.errors_out_pos = stats1.errors_out_pos+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input reset,
	input [3:1] s,
	output reg fr3,
	output reg fr2,
	output reg fr1,
	output reg dfr
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input reset,
	input [3:1] s,
	output reg fr3,
	output reg fr2,
	output reg fr1,
	output reg dfr
);
	parameter A2=0, B1=1, B2=2, C1=3, C2=4, D1=5;
	reg [2:0] state, next;

	always @(posedge clk) begin
		if (reset) state <= A2;
		else state <= next;
	end

	always@(*) begin
		case (state)
			A2: next = s[1] ? B1 : A2;
			B1: next = s[2] ? C1 : (s[1] ? B1 : A2);
			B2: next = s[2] ? C1 : (s[1] ? B2 : A2);
			C1: next = s[3] ? D1 : (s[2] ? C1 : B2);
			C2: next = s[3] ? D1 : (s[2] ? C2 : B2);
			D1: next = s[3] ? D1 : C2;
			default: next = 'x;
		endcase
	end
	reg [3:0] fr;
	assign {fr3, fr2, fr1, dfr} = fr;
	always_comb begin
		case (state)
			A2: fr = 4'b1111;
			B1: fr = 4'b0110;
			B2: fr = 4'b0111;
			C1: fr = 4'b0010;
			C2: fr = 4'b0011;
			D1: fr = 4'b0000;
			default: fr = 'x;
		endcase
	end

endmodule

module stimulus_gen (
	input clk,
	output logic reset,
	output logic [3:1] s,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

	wire [3:0][2:0] val = { 3'h7, 3'h3, 3'h1, 3'h0 };
	integer sval;
	initial begin
		reset <= 1;
		s <= 1;
		reset_test();

		@(posedge clk) s <= 0;
		@(posedge clk) s <= 0;
		@(negedge clk) wavedrom_start("Water rises to highest level, then down to lowest level.");
			@(posedge clk) s <= 0;
			@(posedge clk) s <= 1;
			@(posedge clk) s <= 3;
			@(posedge clk) s <= 7;
			@(posedge clk) s <= 7;
			@(posedge clk) s <= 3;
			@(posedge clk) s <= 3;
			@(posedge clk) s <= 1;
			@(posedge clk) s <= 1;
			@(posedge clk) s <= 0;
			@(posedge clk) s <= 0;
		@(negedge clk) wavedrom_stop();

		sval = 0;
		repeat(1000) begin
			@(posedge clk);
				sval = sval + (sval == 3 ? 0 : $random&1);
				s <= val[sval];
			@(negedge clk);
				sval = sval - (sval == 0 ? 0 : $random&1);
				s <= val[sval];
		end

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_fr3;
		int errortime_fr3;
		int errors_fr2;
		int errortime_fr2;
		int errors_fr1;
		int errortime_fr1;
		int errors_dfr;
		int errortime_dfr;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic reset;
	logic [3:1] s;
	logic fr3_ref;
	logic fr3_dut;
	logic fr2_ref;
	logic fr2_dut;
	logic fr1_ref;
	logic fr1_dut;
	logic dfr_ref;
	logic dfr_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,s,fr3_ref,fr3_dut,fr2_ref,fr2_dut,fr1_ref,fr1_dut,dfr_ref,dfr_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.s );
	reference_module good1 (
		.clk,
		.reset,
		.s,
		.fr3(fr3_ref),
		.fr2(fr2_ref),
		.fr1(fr1_ref),
		.dfr(dfr_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.s,
		.fr3(fr3_dut),
		.fr2(fr2_dut),
		.fr1(fr1_dut),
		.dfr(dfr_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_fr3) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "fr3", stats1.errors_fr3, stats1.errortime_fr3);
		else $display("Hint: Output '%s' has no mismatches.", "fr3");
		if (stats1.errors_fr2) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "fr2", stats1.errors_fr2, stats1.errortime_fr2);
		else $display("Hint: Output '%s' has no mismatches.", "fr2");
		if (stats1.errors_fr1) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "fr1", stats1.errors_fr1, stats1.errortime_fr1);
		else $display("Hint: Output '%s' has no mismatches.", "fr1");
		if (stats1.errors_dfr) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "dfr", stats1.errors_dfr, stats1.errortime_dfr);
		else $display("Hint: Output '%s' has no mismatches.", "dfr");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { fr3_ref, fr2_ref, fr1_ref, dfr_ref } === ( { fr3_ref, fr2_ref, fr1_ref, dfr_ref } ^ { fr3_dut, fr2_dut, fr1_dut, dfr_dut } ^ { fr3_ref, fr2_ref, fr1_ref, dfr_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (fr3_ref !== ( fr3_ref ^ fr3_dut ^ fr3_ref ))
		begin if (stats1.errors_fr3 == 0) stats1.errortime_fr3 = $time;
			stats1.errors_fr3 = stats1.errors_fr3+1'b1; end
		if (fr2_ref !== ( fr2_ref ^ fr2_dut ^ fr2_ref ))
		begin if (stats1.errors_fr2 == 0) stats1.errortime_fr2 = $time;
			stats1.errors_fr2 = stats1.errors_fr2+1'b1; end
		if (fr1_ref !== ( fr1_ref ^ fr1_dut ^ fr1_ref ))
		begin if (stats1.errors_fr1 == 0) stats1.errortime_fr1 = $time;
			stats1.errors_fr1 = stats1.errors_fr1+1'b1; end
		if (dfr_ref !== ( dfr_ref ^ dfr_dut ^ dfr_ref ))
		begin if (stats1.errors_dfr == 0) stats1.errortime_dfr = $time;
			stats1.errors_dfr = stats1.errors_dfr+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input reset,
	input [3:1] s,
	output reg fr3,
	output reg fr2,
	output reg fr1,
	output reg dfr
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input reset,
	input [3:1] s,
	output reg fr3,
	output reg fr2,
	output reg fr1,
	output reg dfr
);
	parameter A2=0, B1=1, B2=2, C1=3, C2=4, D1=5;
	reg [2:0] state, next;

	always @(posedge clk) begin
		if (reset) state <= A2;
		else state <= next;
	end

	always@(*) begin
		case (state)
			A2: next = s[1] ? B1 : A2;
			B1: next = s[2] ? C1 : (s[1] ? B1 : A2);
			B2: next = s[2] ? C1 : (s[1] ? B2 : A2);
			C1: next = s[3] ? D1 : (s[2] ? C1 : B2);
			C2: next = s[3] ? D1 : (s[2] ? C2 : B2);
			D1: next = s[3] ? D1 : C2;
			default: next = 'x;
		endcase
	end
	reg [3:0] fr;
	assign {fr3, fr2, fr1, dfr} = fr;
	always_comb begin
		case (state)
			A2: fr = 4'b1111;
			B1: fr = 4'b0110;
			B2: fr = 4'b0111;
			C1: fr = 4'b0010;
			C2: fr = 4'b0011;
			D1: fr = 4'b0000;
			default: fr = 'x;
		endcase
	end

endmodule

module stimulus_gen (
	input clk,
	output logic reset,
	output logic [3:1] s,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

	wire [3:0][2:0] val = { 3'h7, 3'h3, 3'h1, 3'h0 };
	integer sval;
	initial begin
		reset <= 1;
		s <= 1;
		reset_test();

		@(posedge clk) s <= 0;
		@(posedge clk) s <= 0;
		@(negedge clk) wavedrom_start("Water rises to highest level, then down to lowest level.");
			@(posedge clk) s <= 0;
			@(posedge clk) s <= 1;
			@(posedge clk) s <= 3;
			@(posedge clk) s <= 7;
			@(posedge clk) s <= 7;
			@(posedge clk) s <= 3;
			@(posedge clk) s <= 3;
			@(posedge clk) s <= 1;
			@(posedge clk) s <= 1;
			@(posedge clk) s <= 0;
			@(posedge clk) s <= 0;
		@(negedge clk) wavedrom_stop();

		sval = 0;
		repeat(1000) begin
			@(posedge clk);
				sval = sval + (sval == 3 ? 0 : $random&1);
				s <= val[sval];
			@(negedge clk);
				sval = sval - (sval == 0 ? 0 : $random&1);
				s <= val[sval];
		end

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_fr3;
		int errortime_fr3;
		int errors_fr2;
		int errortime_fr2;
		int errors_fr1;
		int errortime_fr1;
		int errors_dfr;
		int errortime_dfr;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic reset;
	logic [3:1] s;
	logic fr3_ref;
	logic fr3_dut;
	logic fr2_ref;
	logic fr2_dut;
	logic fr1_ref;
	logic fr1_dut;
	logic dfr_ref;
	logic dfr_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,s,fr3_ref,fr3_dut,fr2_ref,fr2_dut,fr1_ref,fr1_dut,dfr_ref,dfr_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.s );
	reference_module good1 (
		.clk,
		.reset,
		.s,
		.fr3(fr3_ref),
		.fr2(fr2_ref),
		.fr1(fr1_ref),
		.dfr(dfr_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.s,
		.fr3(fr3_dut),
		.fr2(fr2_dut),
		.fr1(fr1_dut),
		.dfr(dfr_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_fr3) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "fr3", stats1.errors_fr3, stats1.errortime_fr3);
		else $display("Hint: Output '%s' has no mismatches.", "fr3");
		if (stats1.errors_fr2) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "fr2", stats1.errors_fr2, stats1.errortime_fr2);
		else $display("Hint: Output '%s' has no mismatches.", "fr2");
		if (stats1.errors_fr1) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "fr1", stats1.errors_fr1, stats1.errortime_fr1);
		else $display("Hint: Output '%s' has no mismatches.", "fr1");
		if (stats1.errors_dfr) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "dfr", stats1.errors_dfr, stats1.errortime_dfr);
		else $display("Hint: Output '%s' has no mismatches.", "dfr");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { fr3_ref, fr2_ref, fr1_ref, dfr_ref } === ( { fr3_ref, fr2_ref, fr1_ref, dfr_ref } ^ { fr3_dut, fr2_dut, fr1_dut, dfr_dut } ^ { fr3_ref, fr2_ref, fr1_ref, dfr_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (fr3_ref !== ( fr3_ref ^ fr3_dut ^ fr3_ref ))
		begin if (stats1.errors_fr3 == 0) stats1.errortime_fr3 = $time;
			stats1.errors_fr3 = stats1.errors_fr3+1'b1; end
		if (fr2_ref !== ( fr2_ref ^ fr2_dut ^ fr2_ref ))
		begin if (stats1.errors_fr2 == 0) stats1.errortime_fr2 = $time;
			stats1.errors_fr2 = stats1.errors_fr2+1'b1; end
		if (fr1_ref !== ( fr1_ref ^ fr1_dut ^ fr1_ref ))
		begin if (stats1.errors_fr1 == 0) stats1.errortime_fr1 = $time;
			stats1.errors_fr1 = stats1.errors_fr1+1'b1; end
		if (dfr_ref !== ( dfr_ref ^ dfr_dut ^ dfr_ref ))
		begin if (stats1.errors_dfr == 0) stats1.errortime_dfr = $time;
			stats1.errors_dfr = stats1.errors_dfr+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input [7:0] a,
	input [7:0] b,
	output [7:0] s,
	output overflow
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [7:0] a,
	input [7:0] b,
	output [7:0] s,
	output overflow
);

	wire [8:0] sum = a+b;
	assign s = sum[7:0];
	assign overflow = !(a[7]^b[7]) && (a[7] != s[7]);

endmodule

module stimulus_gen (
	input clk,
	output logic [7:0] a, b,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		{a, b} <= 0;
		@(negedge clk) wavedrom_start();
			@(posedge clk) {a, b} <= 16'h0;
			@(posedge clk) {a, b} <= 16'h0070;
			@(posedge clk) {a, b} <= 16'h7070;
			@(posedge clk) {a, b} <= 16'h7090;
			@(posedge clk) {a, b} <= 16'h9070;
			@(posedge clk) {a, b} <= 16'h9090;
			@(posedge clk) {a, b} <= 16'h90ff;
		@(negedge clk) wavedrom_stop();
		repeat(100) @(posedge clk, negedge clk)
			{a,b} <= $random;

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_s;
		int errortime_s;
		int errors_overflow;
		int errortime_overflow;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic [7:0] a;
	logic [7:0] b;
	logic [7:0] s_ref;
	logic [7:0] s_dut;
	logic overflow_ref;
	logic overflow_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,s_ref,s_dut,overflow_ref,overflow_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b );
	reference_module good1 (
		.a,
		.b,
		.s(s_ref),
		.overflow(overflow_ref) );

	top_module top_module1 (
		.a,
		.b,
		.s(s_dut),
		.overflow(overflow_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_s) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "s", stats1.errors_s, stats1.errortime_s);
		else $display("Hint: Output '%s' has no mismatches.", "s");
		if (stats1.errors_overflow) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "overflow", stats1.errors_overflow, stats1.errortime_overflow);
		else $display("Hint: Output '%s' has no mismatches.", "overflow");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { s_ref, overflow_ref } === ( { s_ref, overflow_ref } ^ { s_dut, overflow_dut } ^ { s_ref, overflow_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (s_ref !== ( s_ref ^ s_dut ^ s_ref ))
		begin if (stats1.errors_s == 0) stats1.errortime_s = $time;
			stats1.errors_s = stats1.errors_s+1'b1; end
		if (overflow_ref !== ( overflow_ref ^ overflow_dut ^ overflow_ref ))
		begin if (stats1.errors_overflow == 0) stats1.errortime_overflow = $time;
			stats1.errors_overflow = stats1.errors_overflow+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input [7:0] a,
	input [7:0] b,
	output [7:0] s,
	output overflow
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [7:0] a,
	input [7:0] b,
	output [7:0] s,
	output overflow
);

	wire [8:0] sum = a+b;
	assign s = sum[7:0];
	assign overflow = !(a[7]^b[7]) && (a[7] != s[7]);

endmodule

module stimulus_gen (
	input clk,
	output logic [7:0] a, b,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		{a, b} <= 0;
		@(negedge clk) wavedrom_start();
			@(posedge clk) {a, b} <= 16'h0;
			@(posedge clk) {a, b} <= 16'h0070;
			@(posedge clk) {a, b} <= 16'h7070;
			@(posedge clk) {a, b} <= 16'h7090;
			@(posedge clk) {a, b} <= 16'h9070;
			@(posedge clk) {a, b} <= 16'h9090;
			@(posedge clk) {a, b} <= 16'h90ff;
		@(negedge clk) wavedrom_stop();
		repeat(100) @(posedge clk, negedge clk)
			{a,b} <= $random;

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_s;
		int errortime_s;
		int errors_overflow;
		int errortime_overflow;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic [7:0] a;
	logic [7:0] b;
	logic [7:0] s_ref;
	logic [7:0] s_dut;
	logic overflow_ref;
	logic overflow_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,s_ref,s_dut,overflow_ref,overflow_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b );
	reference_module good1 (
		.a,
		.b,
		.s(s_ref),
		.overflow(overflow_ref) );

	top_module top_module1 (
		.a,
		.b,
		.s(s_dut),
		.overflow(overflow_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_s) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "s", stats1.errors_s, stats1.errortime_s);
		else $display("Hint: Output '%s' has no mismatches.", "s");
		if (stats1.errors_overflow) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "overflow", stats1.errors_overflow, stats1.errortime_overflow);
		else $display("Hint: Output '%s' has no mismatches.", "overflow");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { s_ref, overflow_ref } === ( { s_ref, overflow_ref } ^ { s_dut, overflow_dut } ^ { s_ref, overflow_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (s_ref !== ( s_ref ^ s_dut ^ s_ref ))
		begin if (stats1.errors_s == 0) stats1.errortime_s = $time;
			stats1.errors_s = stats1.errors_s+1'b1; end
		if (overflow_ref !== ( overflow_ref ^ overflow_dut ^ overflow_ref ))
		begin if (stats1.errors_overflow == 0) stats1.errortime_overflow = $time;
			stats1.errors_overflow = stats1.errors_overflow+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input c,
	input d,
	output [3:0] mux_in
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input c,
	input d,
	output [3:0] mux_in
);

	assign mux_in[0] = c | d;
	assign mux_in[1] = 0;
	assign mux_in[2] = ~d;
	assign mux_in[3] = c&d;

endmodule

module stimulus_gen (
	input clk,
	output logic c, d,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		{c, d} <= 0;
		@(negedge clk) wavedrom_start();
			@(posedge clk) {c, d} <= 2'h0;
			@(posedge clk) {c, d} <= 2'h1;
			@(posedge clk) {c, d} <= 2'h2;
			@(posedge clk) {c, d} <= 2'h3;
		@(negedge clk) wavedrom_stop();
		repeat(50) @(posedge clk, negedge clk)
			{c,d} <= $random;

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_mux_in;
		int errortime_mux_in;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic c;
	logic d;
	logic [3:0] mux_in_ref;
	logic [3:0] mux_in_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,c,d,mux_in_ref,mux_in_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.c,
		.d );
	reference_module good1 (
		.c,
		.d,
		.mux_in(mux_in_ref) );

	top_module top_module1 (
		.c,
		.d,
		.mux_in(mux_in_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_mux_in) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "mux_in", stats1.errors_mux_in, stats1.errortime_mux_in);
		else $display("Hint: Output '%s' has no mismatches.", "mux_in");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { mux_in_ref } === ( { mux_in_ref } ^ { mux_in_dut } ^ { mux_in_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (mux_in_ref !== ( mux_in_ref ^ mux_in_dut ^ mux_in_ref ))
		begin if (stats1.errors_mux_in == 0) stats1.errortime_mux_in = $time;
			stats1.errors_mux_in = stats1.errors_mux_in+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input c,
	input d,
	output [3:0] mux_in
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input c,
	input d,
	output [3:0] mux_in
);

	assign mux_in[0] = c | d;
	assign mux_in[1] = 0;
	assign mux_in[2] = ~d;
	assign mux_in[3] = c&d;

endmodule

module stimulus_gen (
	input clk,
	output logic c, d,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		{c, d} <= 0;
		@(negedge clk) wavedrom_start();
			@(posedge clk) {c, d} <= 2'h0;
			@(posedge clk) {c, d} <= 2'h1;
			@(posedge clk) {c, d} <= 2'h2;
			@(posedge clk) {c, d} <= 2'h3;
		@(negedge clk) wavedrom_stop();
		repeat(50) @(posedge clk, negedge clk)
			{c,d} <= $random;

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_mux_in;
		int errortime_mux_in;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic c;
	logic d;
	logic [3:0] mux_in_ref;
	logic [3:0] mux_in_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,c,d,mux_in_ref,mux_in_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.c,
		.d );
	reference_module good1 (
		.c,
		.d,
		.mux_in(mux_in_ref) );

	top_module top_module1 (
		.c,
		.d,
		.mux_in(mux_in_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_mux_in) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "mux_in", stats1.errors_mux_in, stats1.errortime_mux_in);
		else $display("Hint: Output '%s' has no mismatches.", "mux_in");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { mux_in_ref } === ( { mux_in_ref } ^ { mux_in_dut } ^ { mux_in_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (mux_in_ref !== ( mux_in_ref ^ mux_in_dut ^ mux_in_ref ))
		begin if (stats1.errors_mux_in == 0) stats1.errortime_mux_in = $time;
			stats1.errors_mux_in = stats1.errors_mux_in+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input x,
	output z
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input x,
	output z
);

	reg [2:0] s = 0;

	always @(posedge clk) begin
		s <= { s[2] ^ x, ~s[1] & x, ~s[0] | x };
	end

	assign z = ~|s;

endmodule

module stimulus_gen (
	input clk,
	output logic x,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		x <= 0;
		@(negedge clk) wavedrom_start();
			@(posedge clk) x <= 2'h0;
			@(posedge clk) x <= 2'h0;
			@(posedge clk) x <= 2'h0;
			@(posedge clk) x <= 2'h0;
			@(posedge clk) x <= 2'h1;
			@(posedge clk) x <= 2'h1;
			@(posedge clk) x <= 2'h1;
			@(posedge clk) x <= 2'h1;
		@(negedge clk) wavedrom_stop();
		repeat(100) @(posedge clk, negedge clk)
			x <= $random;

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_z;
		int errortime_z;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic x;
	logic z_ref;
	logic z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,x,z_ref,z_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.x );
	reference_module good1 (
		.clk,
		.x,
		.z(z_ref) );

	top_module top_module1 (
		.clk,
		.x,
		.z(z_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "z", stats1.errors_z, stats1.errortime_z);
		else $display("Hint: Output '%s' has no mismatches.", "z");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { z_ref } === ( { z_ref } ^ { z_dut } ^ { z_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (z_ref !== ( z_ref ^ z_dut ^ z_ref ))
		begin if (stats1.errors_z == 0) stats1.errortime_z = $time;
			stats1.errors_z = stats1.errors_z+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input x,
	output z
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input x,
	output z
);

	reg [2:0] s = 0;

	always @(posedge clk) begin
		s <= { s[2] ^ x, ~s[1] & x, ~s[0] | x };
	end

	assign z = ~|s;

endmodule

module stimulus_gen (
	input clk,
	output logic x,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		x <= 0;
		@(negedge clk) wavedrom_start();
			@(posedge clk) x <= 2'h0;
			@(posedge clk) x <= 2'h0;
			@(posedge clk) x <= 2'h0;
			@(posedge clk) x <= 2'h0;
			@(posedge clk) x <= 2'h1;
			@(posedge clk) x <= 2'h1;
			@(posedge clk) x <= 2'h1;
			@(posedge clk) x <= 2'h1;
		@(negedge clk) wavedrom_stop();
		repeat(100) @(posedge clk, negedge clk)
			x <= $random;

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_z;
		int errortime_z;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic x;
	logic z_ref;
	logic z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,x,z_ref,z_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.x );
	reference_module good1 (
		.clk,
		.x,
		.z(z_ref) );

	top_module top_module1 (
		.clk,
		.x,
		.z(z_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "z", stats1.errors_z, stats1.errortime_z);
		else $display("Hint: Output '%s' has no mismatches.", "z");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { z_ref } === ( { z_ref } ^ { z_dut } ^ { z_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (z_ref !== ( z_ref ^ z_dut ^ z_ref ))
		begin if (stats1.errors_z == 0) stats1.errortime_z = $time;
			stats1.errors_z = stats1.errors_z+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input areset,
	input x,
	output z
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input areset,
	input x,
	output z
);

	parameter A=0,B=1,C=2;
	reg [1:0] state;
	always @(posedge clk, posedge areset) begin
		if (areset)
			state <= A;
		else begin
			case (state)
				A: state <= x ? C : A;
				B: state <= x ? B : C;
				C: state <= x ? B : C;
			endcase
		end
	end

	assign z = (state == C);

endmodule

module stimulus_gen (
	input clk,
	output logic x,
	output logic areset,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);
	reg reset;
	assign areset = reset;

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

	initial begin
		x <= 0;
		reset <= 1;
		@(posedge clk) reset <= 0; x <= 1;
		@(posedge clk) x <= 0;
		reset_test(1);

		@(negedge clk) wavedrom_start();
			@(posedge clk) {reset,x} <= 2'h2;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h0;
		@(negedge clk) wavedrom_stop();
		repeat(400) @(posedge clk, negedge clk)
			{reset,x} <= {($random&31) == 0, ($random&1)==0 };

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_z;
		int errortime_z;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic areset;
	logic x;
	logic z_ref;
	logic z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,areset,x,z_ref,z_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.areset,
		.x );
	reference_module good1 (
		.clk,
		.areset,
		.x,
		.z(z_ref) );

	top_module top_module1 (
		.clk,
		.areset,
		.x,
		.z(z_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "z", stats1.errors_z, stats1.errortime_z);
		else $display("Hint: Output '%s' has no mismatches.", "z");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { z_ref } === ( { z_ref } ^ { z_dut } ^ { z_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (z_ref !== ( z_ref ^ z_dut ^ z_ref ))
		begin if (stats1.errors_z == 0) stats1.errortime_z = $time;
			stats1.errors_z = stats1.errors_z+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input areset,
	input x,
	output z
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input areset,
	input x,
	output z
);

	parameter A=0,B=1,C=2;
	reg [1:0] state;
	always @(posedge clk, posedge areset) begin
		if (areset)
			state <= A;
		else begin
			case (state)
				A: state <= x ? C : A;
				B: state <= x ? B : C;
				C: state <= x ? B : C;
			endcase
		end
	end

	assign z = (state == C);

endmodule

module stimulus_gen (
	input clk,
	output logic x,
	output logic areset,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);
	reg reset;
	assign areset = reset;

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

	initial begin
		x <= 0;
		reset <= 1;
		@(posedge clk) reset <= 0; x <= 1;
		@(posedge clk) x <= 0;
		reset_test(1);

		@(negedge clk) wavedrom_start();
			@(posedge clk) {reset,x} <= 2'h2;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h0;
		@(negedge clk) wavedrom_stop();
		repeat(400) @(posedge clk, negedge clk)
			{reset,x} <= {($random&31) == 0, ($random&1)==0 };

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_z;
		int errortime_z;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic areset;
	logic x;
	logic z_ref;
	logic z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,areset,x,z_ref,z_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.areset,
		.x );
	reference_module good1 (
		.clk,
		.areset,
		.x,
		.z(z_ref) );

	top_module top_module1 (
		.clk,
		.areset,
		.x,
		.z(z_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "z", stats1.errors_z, stats1.errortime_z);
		else $display("Hint: Output '%s' has no mismatches.", "z");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { z_ref } === ( { z_ref } ^ { z_dut } ^ { z_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (z_ref !== ( z_ref ^ z_dut ^ z_ref ))
		begin if (stats1.errors_z == 0) stats1.errortime_z = $time;
			stats1.errors_z = stats1.errors_z+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input areset,
	input x,
	output z
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input areset,
	input x,
	output z
);

	parameter A=0,B=1;
	reg state;
	always @(posedge clk, posedge areset) begin
		if (areset)
			state <= A;
		else begin
			case (state)
				A: state <= x ? B : A;
				B: state <= B;
			endcase
		end
	end

	assign z = (state == A && x==1) | (state == B && x==0);

endmodule

module stimulus_gen (
	input clk,
	output logic x,
	output logic areset,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);
	reg reset;
	assign areset = reset;

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

	initial begin
		x <= 0;
		reset <= 1;
		@(posedge clk) reset <= 0; x <= 1;
		@(posedge clk) x <= 0;
		reset_test(1);

		@(negedge clk) wavedrom_start();
			@(posedge clk) {reset,x} <= 2'h2;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h0;
		@(negedge clk) wavedrom_stop();
		repeat(400) @(posedge clk, negedge clk)
			{reset,x} <= {($random&31) == 0, ($random&1)==0 };

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_z;
		int errortime_z;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic areset;
	logic x;
	logic z_ref;
	logic z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,areset,x,z_ref,z_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.areset,
		.x );
	reference_module good1 (
		.clk,
		.areset,
		.x,
		.z(z_ref) );

	top_module top_module1 (
		.clk,
		.areset,
		.x,
		.z(z_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "z", stats1.errors_z, stats1.errortime_z);
		else $display("Hint: Output '%s' has no mismatches.", "z");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { z_ref } === ( { z_ref } ^ { z_dut } ^ { z_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (z_ref !== ( z_ref ^ z_dut ^ z_ref ))
		begin if (stats1.errors_z == 0) stats1.errortime_z = $time;
			stats1.errors_z = stats1.errors_z+1'b1; end

	end
endmodule


Prompt:
module top_module (
	input clk,
	input areset,
	input x,
	output z
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input areset,
	input x,
	output z
);

	parameter A=0,B=1;
	reg state;
	always @(posedge clk, posedge areset) begin
		if (areset)
			state <= A;
		else begin
			case (state)
				A: state <= x ? B : A;
				B: state <= B;
			endcase
		end
	end

	assign z = (state == A && x==1) | (state == B && x==0);

endmodule

module stimulus_gen (
	input clk,
	output logic x,
	output logic areset,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	input tb_match
);
	reg reset;
	assign areset = reset;

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	task reset_test(input async=0);
		bit arfail, srfail, datafail;

		@(posedge clk);
		@(posedge clk) reset <= 0;
		repeat(3) @(posedge clk);

		@(negedge clk) begin datafail = !tb_match ; reset <= 1; end
		@(posedge clk) arfail = !tb_match;
		@(posedge clk) begin
			srfail = !tb_match;
			reset <= 0;
		end
		if (srfail)
			$display("Hint: Your reset doesn't seem to be working.");
		else if (arfail && (async || !datafail))
			$display("Hint: Your reset should be %0s, but doesn't appear to be.", async ? "asynchronous" : "synchronous");
		// Don't warn about synchronous reset if the half-cycle before is already wrong. It's more likely
		// a functionality error than the reset being implemented asynchronously.

	endtask

	initial begin
		x <= 0;
		reset <= 1;
		@(posedge clk) reset <= 0; x <= 1;
		@(posedge clk) x <= 0;
		reset_test(1);

		@(negedge clk) wavedrom_start();
			@(posedge clk) {reset,x} <= 2'h2;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h1;
			@(posedge clk) {reset,x} <= 2'h0;
			@(posedge clk) {reset,x} <= 2'h0;
		@(negedge clk) wavedrom_stop();
		repeat(400) @(posedge clk, negedge clk)
			{reset,x} <= {($random&31) == 0, ($random&1)==0 };

		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_z;
		int errortime_z;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic areset;
	logic x;
	logic z_ref;
	logic z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,areset,x,z_ref,z_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.areset,
		.x );
	reference_module good1 (
		.clk,
		.areset,
		.x,
		.z(z_ref) );

	top_module top_module1 (
		.clk,
		.areset,
		.x,
		.z(z_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "z", stats1.errors_z, stats1.errortime_z);
		else $display("Hint: Output '%s' has no mismatches.", "z");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { z_ref } === ( { z_ref } ^ { z_dut } ^ { z_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (z_ref !== ( z_ref ^ z_dut ^ z_ref ))
		begin if (stats1.errors_z == 0) stats1.errortime_z = $time;
			stats1.errors_z = stats1.errors_z+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	input [31:0] in,
	output reg [31:0] out);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	input [31:0] in,
	output reg [31:0] out);

	reg [31:0] d_last;

	always @(posedge clk) begin
		d_last <= in;
		if (reset)
			out <= '0;
		else
			out <= out | (~in & d_last);
	end

endmodule

module stimulus_gen (
	input clk,
	input tb_match,
	output reg [31:0] in,
	output reg reset,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		in <= 0;
		reset <= 1;
		@(posedge clk);
		reset <= 1;
		in = 0;
		@(negedge clk) wavedrom_start("Example");
		repeat(1) @(posedge clk);
		reset = 0;
		@(posedge clk) in = 32'h2;
		repeat(4) @(posedge clk);
		in = 32'he;
		repeat(2) @(posedge clk);
		in = 0;
		@(posedge clk) in = 32'h2;
		repeat(2) @(posedge clk);
		reset = 1;
		@(posedge clk);
		reset = 0; in = 0;
		repeat(3) @(posedge clk);

		@(negedge clk) wavedrom_stop();

		@(negedge clk) wavedrom_start("");
		repeat(2) @(posedge clk);
		in <= 1;
		repeat(2) @(posedge clk);
		in <= 0;
		repeat(2) @(negedge clk);
		in <= 6;
		repeat(1) @(negedge clk);
		in <= 0;
		repeat(2) @(posedge clk);
		in <= 32'h10;
		repeat(2) @(posedge clk);
		reset <= 1;
		repeat(1) @(posedge clk);
		in <= 32'h0;
		repeat(1) @(posedge clk);
		reset <= 0;
		repeat(1) @(posedge clk);
		reset <= 1;
		in <= 32'h20;
		repeat(1) @(posedge clk);
		reset <= 0;
		in <= 32'h00;

		repeat(2) @(posedge clk);

		@(negedge clk) wavedrom_stop();

		repeat(200)
			@(posedge clk, negedge clk) begin
				in <= $random;
				reset <= !($random & 15);
			end
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_out;
		int errortime_out;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic reset;
	logic [31:0] in;
	logic [31:0] out_ref;
	logic [31:0] out_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,in,out_ref,out_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.in );
	reference_module good1 (
		.clk,
		.reset,
		.in,
		.out(out_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.in,
		.out(out_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_out) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out", stats1.errors_out, stats1.errortime_out);
		else $display("Hint: Output '%s' has no mismatches.", "out");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { out_ref } === ( { out_ref } ^ { out_dut } ^ { out_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (out_ref !== ( out_ref ^ out_dut ^ out_ref ))
		begin if (stats1.errors_out == 0) stats1.errortime_out = $time;
			stats1.errors_out = stats1.errors_out+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	input [31:0] in,
	output reg [31:0] out);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	input [31:0] in,
	output reg [31:0] out);

	reg [31:0] d_last;

	always @(posedge clk) begin
		d_last <= in;
		if (reset)
			out <= '0;
		else
			out <= out | (~in & d_last);
	end

endmodule

module stimulus_gen (
	input clk,
	input tb_match,
	output reg [31:0] in,
	output reg reset,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		in <= 0;
		reset <= 1;
		@(posedge clk);
		reset <= 1;
		in = 0;
		@(negedge clk) wavedrom_start("Example");
		repeat(1) @(posedge clk);
		reset = 0;
		@(posedge clk) in = 32'h2;
		repeat(4) @(posedge clk);
		in = 32'he;
		repeat(2) @(posedge clk);
		in = 0;
		@(posedge clk) in = 32'h2;
		repeat(2) @(posedge clk);
		reset = 1;
		@(posedge clk);
		reset = 0; in = 0;
		repeat(3) @(posedge clk);

		@(negedge clk) wavedrom_stop();

		@(negedge clk) wavedrom_start("");
		repeat(2) @(posedge clk);
		in <= 1;
		repeat(2) @(posedge clk);
		in <= 0;
		repeat(2) @(negedge clk);
		in <= 6;
		repeat(1) @(negedge clk);
		in <= 0;
		repeat(2) @(posedge clk);
		in <= 32'h10;
		repeat(2) @(posedge clk);
		reset <= 1;
		repeat(1) @(posedge clk);
		in <= 32'h0;
		repeat(1) @(posedge clk);
		reset <= 0;
		repeat(1) @(posedge clk);
		reset <= 1;
		in <= 32'h20;
		repeat(1) @(posedge clk);
		reset <= 0;
		in <= 32'h00;

		repeat(2) @(posedge clk);

		@(negedge clk) wavedrom_stop();

		repeat(200)
			@(posedge clk, negedge clk) begin
				in <= $random;
				reset <= !($random & 15);
			end
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_out;
		int errortime_out;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic reset;
	logic [31:0] in;
	logic [31:0] out_ref;
	logic [31:0] out_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,in,out_ref,out_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.in );
	reference_module good1 (
		.clk,
		.reset,
		.in,
		.out(out_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.in,
		.out(out_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_out) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out", stats1.errors_out, stats1.errortime_out);
		else $display("Hint: Output '%s' has no mismatches.", "out");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { out_ref } === ( { out_ref } ^ { out_dut } ^ { out_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (out_ref !== ( out_ref ^ out_dut ^ out_ref ))
		begin if (stats1.errors_out == 0) stats1.errortime_out = $time;
			stats1.errors_out = stats1.errors_out+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input [7:0] in,
	output reg [7:0] pedge);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input [7:0] in,
	output reg [7:0] pedge);

	reg [7:0] d_last;

	always @(posedge clk) begin
		d_last <= in;
		pedge <= in & ~d_last;
	end

endmodule

module stimulus_gen (
	input clk,
	input tb_match,
	output reg [7:0] in,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		in <= 0;
		@(posedge clk);
		wavedrom_start("");
		repeat(2) @(posedge clk);
		in <= 1;
		repeat(4) @(posedge clk);
		in <= 0;
		repeat(4) @(negedge clk);
		in <= 6;
		repeat(2) @(negedge clk);
		in <= 0;
		repeat(2) @(posedge clk);
		wavedrom_stop();

		repeat(200)
			@(posedge clk, negedge clk) in <= $random;
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_pedge;
		int errortime_pedge;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic [7:0] in;
	logic [7:0] pedge_ref;
	logic [7:0] pedge_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,in,pedge_ref,pedge_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.in );
	reference_module good1 (
		.clk,
		.in,
		.pedge(pedge_ref) );

	top_module top_module1 (
		.clk,
		.in,
		.pedge(pedge_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_pedge) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "pedge", stats1.errors_pedge, stats1.errortime_pedge);
		else $display("Hint: Output '%s' has no mismatches.", "pedge");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { pedge_ref } === ( { pedge_ref } ^ { pedge_dut } ^ { pedge_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (pedge_ref !== ( pedge_ref ^ pedge_dut ^ pedge_ref ))
		begin if (stats1.errors_pedge == 0) stats1.errortime_pedge = $time;
			stats1.errors_pedge = stats1.errors_pedge+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input [7:0] in,
	output reg [7:0] pedge);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input [7:0] in,
	output reg [7:0] pedge);

	reg [7:0] d_last;

	always @(posedge clk) begin
		d_last <= in;
		pedge <= in & ~d_last;
	end

endmodule

module stimulus_gen (
	input clk,
	input tb_match,
	output reg [7:0] in,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		in <= 0;
		@(posedge clk);
		wavedrom_start("");
		repeat(2) @(posedge clk);
		in <= 1;
		repeat(4) @(posedge clk);
		in <= 0;
		repeat(4) @(negedge clk);
		in <= 6;
		repeat(2) @(negedge clk);
		in <= 0;
		repeat(2) @(posedge clk);
		wavedrom_stop();

		repeat(200)
			@(posedge clk, negedge clk) in <= $random;
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_pedge;
		int errortime_pedge;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic [7:0] in;
	logic [7:0] pedge_ref;
	logic [7:0] pedge_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,in,pedge_ref,pedge_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.in );
	reference_module good1 (
		.clk,
		.in,
		.pedge(pedge_ref) );

	top_module top_module1 (
		.clk,
		.in,
		.pedge(pedge_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_pedge) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "pedge", stats1.errors_pedge, stats1.errortime_pedge);
		else $display("Hint: Output '%s' has no mismatches.", "pedge");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { pedge_ref } === ( { pedge_ref } ^ { pedge_dut } ^ { pedge_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (pedge_ref !== ( pedge_ref ^ pedge_dut ^ pedge_ref ))
		begin if (stats1.errors_pedge == 0) stats1.errortime_pedge = $time;
			stats1.errors_pedge = stats1.errors_pedge+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input [7:0] in,
	output reg [7:0] anyedge);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input [7:0] in,
	output reg [7:0] anyedge);

	reg [7:0] d_last;

	always @(posedge clk) begin
		d_last <= in;
		anyedge <= in ^ d_last;
	end

endmodule

module stimulus_gen (
	input clk,
	input tb_match,
	output reg [7:0] in,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable
);

// Add two ports to module stimulus_gen:
//    output [511:0] wavedrom_title
//    output reg wavedrom_enable

	task wavedrom_start(input[511:0] title = "");
	endtask

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		in <= 0;
		@(posedge clk);
		@(negedge clk) wavedrom_start("");
		repeat(2) @(posedge clk);
		in <= 1;
		repeat(4) @(posedge clk);
		in <= 0;
		repeat(4) @(negedge clk);
		in <= 6;
		repeat(2) @(negedge clk);
		in <= 0;
		repeat(2) @(posedge clk);
		@(negedge clk) wavedrom_stop();

		repeat(200)
			@(posedge clk, negedge clk) in <= $random;
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_anyedge;
		int errortime_anyedge;

		int clocks;
	} stats;

	stats stats1;

	wire[511:0] wavedrom_title;
	wire wavedrom_enable;
	int wavedrom_hide_after_time;

	reg clk=0;
	initial forever
		#5 clk = ~clk;

	logic [7:0] in;
	logic [7:0] anyedge_ref;
	logic [7:0] anyedge_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,in,anyedge_ref,anyedge_dut );
	end

	wire tb_match;		// Verification
	wire tb_mismatch = ~tb_match;

	stimulus_gen stim1 (
		.clk,
		.* ,
		.in );
	reference_module good1 (
		.clk,
		.in,
		.anyedge(anyedge_ref) );

	top_module top_module1 (
		.clk,
		.in,
		.anyedge(anyedge_dut) );

	bit strobe = 0;
	task wait_for_end_of_timestep;
		repeat(5) begin
			strobe <= !strobe;  // Try to delay until the very end of the time step.
			@(strobe);
		end
	endtask

	final begin
		if (stats1.errors_anyedge) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "anyedge", stats1.errors_anyedge, stats1.errortime_anyedge);
		else $display("Hint: Output '%s' has no mismatches.", "anyedge");

		$display("Hint: Total mismatched samples is %1d out of %1d samples\n", stats1.errors, stats1.clocks);
		$display("Simulation finished at %0d ps", $time);
		$display("Mismatches: %1d in %1d samples", stats1.errors, stats1.clocks);
	end

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { anyedge_ref } === ( { anyedge_ref } ^ { anyedge_dut } ^ { anyedge_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (anyedge_ref !== ( anyedge_ref ^ anyedge_dut ^ anyedge_ref ))
		begin if (stats1.errors_anyedge == 0) stats1.errortime_anyedge = $time;
			stats1.errors_anyedge = stats1.errors_anyedge+1'b1; end

	end
endmodule