Prompt:
module top_module (
	input [254:0] in,
	output reg [7:0] out
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [254:0] in,
	output reg [7:0] out
);

	always_comb  begin
		out = 0;
		for (int i=0;i<255;i++)
			out = out + in[i];
	end

endmodule

module stimulus_gen (
	input clk,
	output logic [254:0] 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 <= 255'h0;
		wavedrom_start("");
		@(posedge clk, negedge clk) in <= 255'h0;
		@(posedge clk, negedge clk) in <= 255'h0;
		@(posedge clk, negedge clk) in <= 255'h1;
		@(posedge clk, negedge clk) in <= 255'h1;
		@(posedge clk, negedge clk) in <= 255'h3;
		@(posedge clk, negedge clk) in <= 255'h3;
		@(posedge clk, negedge clk) in <= 255'h7;
		@(posedge clk, negedge clk) in <= 255'haaaa;
		@(posedge clk, negedge clk) in <= 255'hf00000;
		@(posedge clk, negedge clk) in <= 255'h0;
		wavedrom_stop();
		repeat (200) @(posedge clk, negedge clk) begin
			in <= {$random, $random, $random, $random, $random, $random, $random, $random};
		end
		@(posedge clk);
		in <= '0;
		@(posedge clk)
		in <= '1;
		@(posedge clk)
		#1 $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 [254:0] in;
	logic [7:0] out_ref;
	logic [7:0] out_dut;

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

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

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

	top_module top_module1 (
		.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 [2:0] in,
	output [1:0] out
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [2:0] in,
	output [1:0] out
);

	assign out = in[0]+in[1]+in[2];

endmodule

module stimulus_gen (
	input clk,
	output logic [2:0] 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 <= 7;
		@(negedge clk);
		wavedrom_start();
			repeat(9) @(posedge clk) in <= in + 1'b1;
		@(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_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 [2:0] in;
	logic [1:0] out_ref;
	logic [1:0] out_dut;

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

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

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

	top_module top_module1 (
		.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 [2:0] in,
	output [1:0] out
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [2:0] in,
	output [1:0] out
);

	assign out = in[0]+in[1]+in[2];

endmodule

module stimulus_gen (
	input clk,
	output logic [2:0] 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 <= 7;
		@(negedge clk);
		wavedrom_start();
			repeat(9) @(posedge clk) in <= in + 1'b1;
		@(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_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 [2:0] in;
	logic [1:0] out_ref;
	logic [1:0] out_dut;

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

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

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

	top_module top_module1 (
		.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 [7:0] in,
	output parity
);

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

	assign parity = ^in;

endmodule

module stimulus_gen (
	input clk,
	output logic [7:0] in
);

	initial begin
		repeat(100) @(posedge clk, negedge clk)
			in <= $random;
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_parity;
		int errortime_parity;

		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 parity_ref;
	logic parity_dut;

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

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.in );
	reference_module good1 (
		.in,
		.parity(parity_ref) );

	top_module top_module1 (
		.in,
		.parity(parity_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_parity) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "parity", stats1.errors_parity, stats1.errortime_parity);
		else $display("Hint: Output '%s' has no mismatches.", "parity");

		$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 = ( { parity_ref } === ( { parity_ref } ^ { parity_dut } ^ { parity_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 (parity_ref !== ( parity_ref ^ parity_dut ^ parity_ref ))
		begin if (stats1.errors_parity == 0) stats1.errortime_parity = $time;
			stats1.errors_parity = stats1.errors_parity+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	output reg [9:0] q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	output reg [9:0] q);

	always @(posedge clk)
		if (reset || q == 999)
			q <= 0;
		else
			q <= q+1;

endmodule

module stimulus_gen (
	input clk,
	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

	initial begin
		reset <= 1;
		wavedrom_start("Synchronous reset");
		reset_test();
		repeat(5) @(posedge clk);
		wavedrom_stop();

		reset <= 0;

		repeat(989) @(negedge clk);
		wavedrom_start("Wrap around behaviour");
		repeat(14)@(posedge clk);
		wavedrom_stop();

		repeat(2000) @(posedge clk, negedge clk) begin
			reset <= !($random & 127);
		end
		reset <= 0;
		repeat(2000) @(posedge clk);

		#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 reset;
	logic [9:0] q_ref;
	logic [9:0] q_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.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 reset,
	output reg [9:0] q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	output reg [9:0] q);

	always @(posedge clk)
		if (reset || q == 999)
			q <= 0;
		else
			q <= q+1;

endmodule

module stimulus_gen (
	input clk,
	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

	initial begin
		reset <= 1;
		wavedrom_start("Synchronous reset");
		reset_test();
		repeat(5) @(posedge clk);
		wavedrom_stop();

		reset <= 0;

		repeat(989) @(negedge clk);
		wavedrom_start("Wrap around behaviour");
		repeat(14)@(posedge clk);
		wavedrom_stop();

		repeat(2000) @(posedge clk, negedge clk) begin
			reset <= !($random & 127);
		end
		reset <= 0;
		repeat(2000) @(posedge clk);

		#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 reset;
	logic [9:0] q_ref;
	logic [9:0] q_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.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 wire clk,
	input wire reset,
	input wire data,
    output wire [3:0] count,
    output reg counting,
    output reg done,
    input wire ack );

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
`default_nettype none
module reference_module(
	input wire clk,
	input wire reset,
	input wire data,
    output wire [3:0] count,
    output reg counting,
    output reg done,
    input wire ack );

	typedef enum logic[3:0] {
		S, S1, S11, S110, B0, B1, B2, B3, Count, Wait
	} States;

	States state, next;

	reg shift_ena;
	reg [9:0] fcount;
	reg [3:0] scount;
	wire done_counting = (scount == 0) && (fcount == 999);

	always_comb begin
		case (state)
			S: next = States'(data ? S1: S);
			S1: next = States'(data ? S11: S);
			S11: next = States'(data ? S11 : S110);
			S110: next = States'(data ? B0 : S);
			B0: next = B1;
			B1: next = B2;
			B2: next = B3;
			B3: next = Count;
			Count: next = States'(done_counting ? Wait : Count);
			Wait: next = States'(ack ? S : Wait);
			default: next = States'(4'bx);
		endcase
	end

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

	always_comb begin
		shift_ena = 0; counting = 0; done = 0;
		if (state == B0 || state == B1 || state == B2 || state == B3)
			shift_ena = 1;
		if (state == Count)
			counting = 1;
		if (state == Wait)
			done = 1;

		if (|state === 1'bx) begin
			{shift_ena, counting, done} = 'x;
		end
	end

	// Shift register
	always @(posedge clk) begin
		if (shift_ena)
			scount <= {scount[2:0], data};
		else if (counting && fcount == 999)
			scount <= scount - 1'b1;
	end

	// Fast counter
	always @(posedge clk)
		if (!counting)
			fcount <= 10'h0;
		else if (fcount == 999)
			fcount <= 10'h0;
		else
			fcount <= fcount + 1'b1;

	assign count = counting ? scount : 'x;

endmodule

module stimulus_gen (
	input wire clk,
	output reg reset,
	output reg data,
	output reg ack,
	input wire tb_match,
	input wire counting_dut
);
	bit failed = 0;
	int counting_cycles = 0;

	always @(posedge clk, negedge clk)
		if (!tb_match)
			failed <= 1;

	always @(posedge clk)
		if (counting_dut)
			counting_cycles++;

	initial begin

		@(posedge clk);
		failed <= 0;
		reset <= 1;
		data <= 0;
		ack <= 1'bx;
		@(posedge clk)
			data <= 1;
			reset <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk);
			data <= 1'bx;
		repeat(2000) @(posedge clk);
			ack <= 1'b0;
		repeat(3) @(posedge clk);
			ack <= 1'b1;
		@(posedge clk);
			ack <= 1'b0;
			data <= 1'b1;
		if (counting_cycles != 2000)
			$display("Hint: The first test case should count for 2000 cycles. Your circuit counted %0d", counting_cycles);
		counting_cycles <= 0;
		@(posedge clk);
			ack <= 1'bx;
			data <= 1'b1;
		@(posedge clk);
			data <= 1'b0;
		@(posedge clk);
			data <= 1'b1;
		@(posedge clk);	data <= 1'b1;
		@(posedge clk);	data <= 1'b1;
		@(posedge clk);	data <= 1'b1;
		@(posedge clk);	data <= 1'b0;
		repeat(14800) @(posedge clk);
		ack <= 1'b0;
		repeat(400) @(posedge clk);

		if (counting_cycles != 15000)
			$display("Hint: The second test case should count for 15000 cycles. Your circuit counted %0d", counting_cycles);
		counting_cycles <= 0;

		if (failed)
			$display("Hint: Your FSM didn't pass the sample timing diagram posted with the problem statement. Perhaps try debugging that?");

		repeat(1000) @(posedge clk, negedge clk) begin
			reset <= !($random & 8191);
			data <= $random;
			ack <= !($random & 31);
		end
		repeat(100000) @(posedge clk) begin
			reset <= !($random & 8191);
			data <= $random;
			ack <= !($random & 31);
		end

		#1 $finish;
	end

endmodule
module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_count;
		int errortime_count;
		int errors_counting;
		int errortime_counting;
		int errors_done;
		int errortime_done;

		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 data;
	logic ack;
	logic [3:0] count_ref;
	logic [3:0] count_dut;
	logic counting_ref;
	logic counting_dut;
	logic done_ref;
	logic done_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,data,ack,count_ref,count_dut,counting_ref,counting_dut,done_ref,done_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.data,
		.ack );
	reference_module good1 (
		.clk,
		.reset,
		.data,
		.ack,
		.count(count_ref),
		.counting(counting_ref),
		.done(done_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.data,
		.ack,
		.count(count_dut),
		.counting(counting_dut),
		.done(done_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_count) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "count", stats1.errors_count, stats1.errortime_count);
		else $display("Hint: Output '%s' has no mismatches.", "count");
		if (stats1.errors_counting) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "counting", stats1.errors_counting, stats1.errortime_counting);
		else $display("Hint: Output '%s' has no mismatches.", "counting");
		if (stats1.errors_done) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "done", stats1.errors_done, stats1.errortime_done);
		else $display("Hint: Output '%s' has no mismatches.", "done");

		$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 = ( { count_ref, counting_ref, done_ref } === ( { count_ref, counting_ref, done_ref } ^ { count_dut, counting_dut, done_dut } ^ { count_ref, counting_ref, done_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 (count_ref !== ( count_ref ^ count_dut ^ count_ref ))
		begin if (stats1.errors_count == 0) stats1.errortime_count = $time;
			stats1.errors_count = stats1.errors_count+1'b1; end
		if (counting_ref !== ( counting_ref ^ counting_dut ^ counting_ref ))
		begin if (stats1.errors_counting == 0) stats1.errortime_counting = $time;
			stats1.errors_counting = stats1.errors_counting+1'b1; end
		if (done_ref !== ( done_ref ^ done_dut ^ done_ref ))
		begin if (stats1.errors_done == 0) stats1.errortime_done = $time;
			stats1.errors_done = stats1.errors_done+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input wire clk,
	input wire reset,
	input wire data,
    output wire [3:0] count,
    output reg counting,
    output reg done,
    input wire ack );

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
`default_nettype none
module reference_module(
	input wire clk,
	input wire reset,
	input wire data,
    output wire [3:0] count,
    output reg counting,
    output reg done,
    input wire ack );

	typedef enum logic[3:0] {
		S, S1, S11, S110, B0, B1, B2, B3, Count, Wait
	} States;

	States state, next;

	reg shift_ena;
	reg [9:0] fcount;
	reg [3:0] scount;
	wire done_counting = (scount == 0) && (fcount == 999);

	always_comb begin
		case (state)
			S: next = States'(data ? S1: S);
			S1: next = States'(data ? S11: S);
			S11: next = States'(data ? S11 : S110);
			S110: next = States'(data ? B0 : S);
			B0: next = B1;
			B1: next = B2;
			B2: next = B3;
			B3: next = Count;
			Count: next = States'(done_counting ? Wait : Count);
			Wait: next = States'(ack ? S : Wait);
			default: next = States'(4'bx);
		endcase
	end

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

	always_comb begin
		shift_ena = 0; counting = 0; done = 0;
		if (state == B0 || state == B1 || state == B2 || state == B3)
			shift_ena = 1;
		if (state == Count)
			counting = 1;
		if (state == Wait)
			done = 1;

		if (|state === 1'bx) begin
			{shift_ena, counting, done} = 'x;
		end
	end

	// Shift register
	always @(posedge clk) begin
		if (shift_ena)
			scount <= {scount[2:0], data};
		else if (counting && fcount == 999)
			scount <= scount - 1'b1;
	end

	// Fast counter
	always @(posedge clk)
		if (!counting)
			fcount <= 10'h0;
		else if (fcount == 999)
			fcount <= 10'h0;
		else
			fcount <= fcount + 1'b1;

	assign count = counting ? scount : 'x;

endmodule

module stimulus_gen (
	input wire clk,
	output reg reset,
	output reg data,
	output reg ack,
	input wire tb_match,
	input wire counting_dut
);
	bit failed = 0;
	int counting_cycles = 0;

	always @(posedge clk, negedge clk)
		if (!tb_match)
			failed <= 1;

	always @(posedge clk)
		if (counting_dut)
			counting_cycles++;

	initial begin

		@(posedge clk);
		failed <= 0;
		reset <= 1;
		data <= 0;
		ack <= 1'bx;
		@(posedge clk)
			data <= 1;
			reset <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk);
			data <= 1'bx;
		repeat(2000) @(posedge clk);
			ack <= 1'b0;
		repeat(3) @(posedge clk);
			ack <= 1'b1;
		@(posedge clk);
			ack <= 1'b0;
			data <= 1'b1;
		if (counting_cycles != 2000)
			$display("Hint: The first test case should count for 2000 cycles. Your circuit counted %0d", counting_cycles);
		counting_cycles <= 0;
		@(posedge clk);
			ack <= 1'bx;
			data <= 1'b1;
		@(posedge clk);
			data <= 1'b0;
		@(posedge clk);
			data <= 1'b1;
		@(posedge clk);	data <= 1'b1;
		@(posedge clk);	data <= 1'b1;
		@(posedge clk);	data <= 1'b1;
		@(posedge clk);	data <= 1'b0;
		repeat(14800) @(posedge clk);
		ack <= 1'b0;
		repeat(400) @(posedge clk);

		if (counting_cycles != 15000)
			$display("Hint: The second test case should count for 15000 cycles. Your circuit counted %0d", counting_cycles);
		counting_cycles <= 0;

		if (failed)
			$display("Hint: Your FSM didn't pass the sample timing diagram posted with the problem statement. Perhaps try debugging that?");

		repeat(1000) @(posedge clk, negedge clk) begin
			reset <= !($random & 8191);
			data <= $random;
			ack <= !($random & 31);
		end
		repeat(100000) @(posedge clk) begin
			reset <= !($random & 8191);
			data <= $random;
			ack <= !($random & 31);
		end

		#1 $finish;
	end

endmodule
module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_count;
		int errortime_count;
		int errors_counting;
		int errortime_counting;
		int errors_done;
		int errortime_done;

		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 data;
	logic ack;
	logic [3:0] count_ref;
	logic [3:0] count_dut;
	logic counting_ref;
	logic counting_dut;
	logic done_ref;
	logic done_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,data,ack,count_ref,count_dut,counting_ref,counting_dut,done_ref,done_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.data,
		.ack );
	reference_module good1 (
		.clk,
		.reset,
		.data,
		.ack,
		.count(count_ref),
		.counting(counting_ref),
		.done(done_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.data,
		.ack,
		.count(count_dut),
		.counting(counting_dut),
		.done(done_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_count) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "count", stats1.errors_count, stats1.errortime_count);
		else $display("Hint: Output '%s' has no mismatches.", "count");
		if (stats1.errors_counting) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "counting", stats1.errors_counting, stats1.errortime_counting);
		else $display("Hint: Output '%s' has no mismatches.", "counting");
		if (stats1.errors_done) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "done", stats1.errors_done, stats1.errortime_done);
		else $display("Hint: Output '%s' has no mismatches.", "done");

		$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 = ( { count_ref, counting_ref, done_ref } === ( { count_ref, counting_ref, done_ref } ^ { count_dut, counting_dut, done_dut } ^ { count_ref, counting_ref, done_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 (count_ref !== ( count_ref ^ count_dut ^ count_ref ))
		begin if (stats1.errors_count == 0) stats1.errortime_count = $time;
			stats1.errors_count = stats1.errors_count+1'b1; end
		if (counting_ref !== ( counting_ref ^ counting_dut ^ counting_ref ))
		begin if (stats1.errors_counting == 0) stats1.errortime_counting = $time;
			stats1.errors_counting = stats1.errors_counting+1'b1; end
		if (done_ref !== ( done_ref ^ done_dut ^ done_ref ))
		begin if (stats1.errors_done == 0) stats1.errortime_done = $time;
			stats1.errors_done = stats1.errors_done+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	input data,
    output reg shift_ena,
    output reg counting,
    input done_counting,
    output reg done,
    input ack );

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	input data,
    output reg shift_ena,
    output reg counting,
    input done_counting,
    output reg done,
    input ack );

	typedef enum logic[3:0] {
		S, S1, S11, S110, B0, B1, B2, B3, Count, Wait
	} States;

	States state, next;

	always_comb begin
		case (state)
			S: next = States'(data ? S1: S);
			S1: next = States'(data ? S11: S);
			S11: next = States'(data ? S11 : S110);
			S110: next = States'(data ? B0 : S);
			B0: next = B1;
			B1: next = B2;
			B2: next = B3;
			B3: next = Count;
			Count: next = States'(done_counting ? Wait : Count);
			Wait: next = States'(ack ? S : Wait);
			default: next = States'(4'bx);
		endcase
	end

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

	always_comb begin
		shift_ena = 0; counting = 0; done = 0;
		if (state == B0 || state == B1 || state == B2 || state == B3)
			shift_ena = 1;
		if (state == Count)
			counting = 1;
		if (state == Wait)
			done = 1;

		if (|state === 1'bx) begin
			{shift_ena, counting, done} = 'x;
		end

	end

endmodule

module stimulus_gen (
	input clk,
	output reg reset,
	output reg data, done_counting, ack,
	input tb_match
);
	bit failed = 0;

	always @(posedge clk, negedge clk)
		if (!tb_match)
			failed <= 1;

	initial begin

		@(posedge clk);
		failed <= 0;
		reset <= 1;
		data <= 0;
		done_counting <= 1'bx;
		ack <= 1'bx;
		@(posedge clk)
			data <= 1;
			reset <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk);
			data <= 1'bx;
		repeat(4) @(posedge clk);
			done_counting <= 1'b0;
		repeat(4) @(posedge clk);
			done_counting <= 1'b1;
		@(posedge clk);
			done_counting <= 1'bx;
			ack <= 1'b0;
		repeat(3) @(posedge clk);
			ack <= 1'b1;
		@(posedge clk);
			ack <= 1'b0;
			data <= 1'b1;
		@(posedge clk);
			ack <= 1'bx;
			data <= 1'b1;
		@(posedge clk);
			data <= 1'b0;
		@(posedge clk);
			data <= 1'b1;
		@(posedge clk);
			data <= 1'bx;
		repeat(4) @(posedge clk);
			done_counting <= 1'b0;
		repeat(4) @(posedge clk);
			done_counting <= 1'b1;
		@(posedge clk);

		if (failed)
			$display("Hint: Your FSM didn't pass the sample timing diagram posted with the problem statement. Perhaps try debugging that?");

		repeat(5000) @(posedge clk, negedge clk) begin
			reset <= !($random & 255);
			data <= $random;
			done_counting <= !($random & 31);
			ack <= !($random & 31);
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_shift_ena;
		int errortime_shift_ena;
		int errors_counting;
		int errortime_counting;
		int errors_done;
		int errortime_done;

		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 data;
	logic done_counting;
	logic ack;
	logic shift_ena_ref;
	logic shift_ena_dut;
	logic counting_ref;
	logic counting_dut;
	logic done_ref;
	logic done_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,data,done_counting,ack,shift_ena_ref,shift_ena_dut,counting_ref,counting_dut,done_ref,done_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.data,
		.done_counting,
		.ack );
	reference_module good1 (
		.clk,
		.reset,
		.data,
		.done_counting,
		.ack,
		.shift_ena(shift_ena_ref),
		.counting(counting_ref),
		.done(done_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.data,
		.done_counting,
		.ack,
		.shift_ena(shift_ena_dut),
		.counting(counting_dut),
		.done(done_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_shift_ena) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "shift_ena", stats1.errors_shift_ena, stats1.errortime_shift_ena);
		else $display("Hint: Output '%s' has no mismatches.", "shift_ena");
		if (stats1.errors_counting) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "counting", stats1.errors_counting, stats1.errortime_counting);
		else $display("Hint: Output '%s' has no mismatches.", "counting");
		if (stats1.errors_done) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "done", stats1.errors_done, stats1.errortime_done);
		else $display("Hint: Output '%s' has no mismatches.", "done");

		$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 = ( { shift_ena_ref, counting_ref, done_ref } === ( { shift_ena_ref, counting_ref, done_ref } ^ { shift_ena_dut, counting_dut, done_dut } ^ { shift_ena_ref, counting_ref, done_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 (shift_ena_ref !== ( shift_ena_ref ^ shift_ena_dut ^ shift_ena_ref ))
		begin if (stats1.errors_shift_ena == 0) stats1.errortime_shift_ena = $time;
			stats1.errors_shift_ena = stats1.errors_shift_ena+1'b1; end
		if (counting_ref !== ( counting_ref ^ counting_dut ^ counting_ref ))
		begin if (stats1.errors_counting == 0) stats1.errortime_counting = $time;
			stats1.errors_counting = stats1.errors_counting+1'b1; end
		if (done_ref !== ( done_ref ^ done_dut ^ done_ref ))
		begin if (stats1.errors_done == 0) stats1.errortime_done = $time;
			stats1.errors_done = stats1.errors_done+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	input data,
    output reg shift_ena,
    output reg counting,
    input done_counting,
    output reg done,
    input ack );

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	input data,
    output reg shift_ena,
    output reg counting,
    input done_counting,
    output reg done,
    input ack );

	typedef enum logic[3:0] {
		S, S1, S11, S110, B0, B1, B2, B3, Count, Wait
	} States;

	States state, next;

	always_comb begin
		case (state)
			S: next = States'(data ? S1: S);
			S1: next = States'(data ? S11: S);
			S11: next = States'(data ? S11 : S110);
			S110: next = States'(data ? B0 : S);
			B0: next = B1;
			B1: next = B2;
			B2: next = B3;
			B3: next = Count;
			Count: next = States'(done_counting ? Wait : Count);
			Wait: next = States'(ack ? S : Wait);
			default: next = States'(4'bx);
		endcase
	end

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

	always_comb begin
		shift_ena = 0; counting = 0; done = 0;
		if (state == B0 || state == B1 || state == B2 || state == B3)
			shift_ena = 1;
		if (state == Count)
			counting = 1;
		if (state == Wait)
			done = 1;

		if (|state === 1'bx) begin
			{shift_ena, counting, done} = 'x;
		end

	end

endmodule

module stimulus_gen (
	input clk,
	output reg reset,
	output reg data, done_counting, ack,
	input tb_match
);
	bit failed = 0;

	always @(posedge clk, negedge clk)
		if (!tb_match)
			failed <= 1;

	initial begin

		@(posedge clk);
		failed <= 0;
		reset <= 1;
		data <= 0;
		done_counting <= 1'bx;
		ack <= 1'bx;
		@(posedge clk)
			data <= 1;
			reset <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 1;
		@(posedge clk) data <= 0;
		@(posedge clk) data <= 1;
		@(posedge clk);
			data <= 1'bx;
		repeat(4) @(posedge clk);
			done_counting <= 1'b0;
		repeat(4) @(posedge clk);
			done_counting <= 1'b1;
		@(posedge clk);
			done_counting <= 1'bx;
			ack <= 1'b0;
		repeat(3) @(posedge clk);
			ack <= 1'b1;
		@(posedge clk);
			ack <= 1'b0;
			data <= 1'b1;
		@(posedge clk);
			ack <= 1'bx;
			data <= 1'b1;
		@(posedge clk);
			data <= 1'b0;
		@(posedge clk);
			data <= 1'b1;
		@(posedge clk);
			data <= 1'bx;
		repeat(4) @(posedge clk);
			done_counting <= 1'b0;
		repeat(4) @(posedge clk);
			done_counting <= 1'b1;
		@(posedge clk);

		if (failed)
			$display("Hint: Your FSM didn't pass the sample timing diagram posted with the problem statement. Perhaps try debugging that?");

		repeat(5000) @(posedge clk, negedge clk) begin
			reset <= !($random & 255);
			data <= $random;
			done_counting <= !($random & 31);
			ack <= !($random & 31);
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_shift_ena;
		int errortime_shift_ena;
		int errors_counting;
		int errortime_counting;
		int errors_done;
		int errortime_done;

		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 data;
	logic done_counting;
	logic ack;
	logic shift_ena_ref;
	logic shift_ena_dut;
	logic counting_ref;
	logic counting_dut;
	logic done_ref;
	logic done_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,data,done_counting,ack,shift_ena_ref,shift_ena_dut,counting_ref,counting_dut,done_ref,done_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.data,
		.done_counting,
		.ack );
	reference_module good1 (
		.clk,
		.reset,
		.data,
		.done_counting,
		.ack,
		.shift_ena(shift_ena_ref),
		.counting(counting_ref),
		.done(done_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.data,
		.done_counting,
		.ack,
		.shift_ena(shift_ena_dut),
		.counting(counting_dut),
		.done(done_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_shift_ena) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "shift_ena", stats1.errors_shift_ena, stats1.errortime_shift_ena);
		else $display("Hint: Output '%s' has no mismatches.", "shift_ena");
		if (stats1.errors_counting) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "counting", stats1.errors_counting, stats1.errortime_counting);
		else $display("Hint: Output '%s' has no mismatches.", "counting");
		if (stats1.errors_done) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "done", stats1.errors_done, stats1.errortime_done);
		else $display("Hint: Output '%s' has no mismatches.", "done");

		$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 = ( { shift_ena_ref, counting_ref, done_ref } === ( { shift_ena_ref, counting_ref, done_ref } ^ { shift_ena_dut, counting_dut, done_dut } ^ { shift_ena_ref, counting_ref, done_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 (shift_ena_ref !== ( shift_ena_ref ^ shift_ena_dut ^ shift_ena_ref ))
		begin if (stats1.errors_shift_ena == 0) stats1.errortime_shift_ena = $time;
			stats1.errors_shift_ena = stats1.errors_shift_ena+1'b1; end
		if (counting_ref !== ( counting_ref ^ counting_dut ^ counting_ref ))
		begin if (stats1.errors_counting == 0) stats1.errortime_counting = $time;
			stats1.errors_counting = stats1.errors_counting+1'b1; end
		if (done_ref !== ( done_ref ^ done_dut ^ done_ref ))
		begin if (stats1.errors_done == 0) stats1.errortime_done = $time;
			stats1.errors_done = stats1.errors_done+1'b1; end

	end
endmodule


Prompt:
module top_module(
    input d,
    input done_counting,
    input ack,
    input [9:0] state,    // 10-bit one-hot current state
    output B3_next,
    output S_next,
    output S1_next,
    output Count_next,
    output Wait_next,
    output done,
    output counting,
    output shift_ena
 );

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
    input d,
    input done_counting,
    input ack,
    input [9:0] state,    // 10-bit one-hot current state
    output B3_next,
    output S_next,
    output S1_next,
    output Count_next,
    output Wait_next,
    output done,
    output counting,
    output shift_ena
 );

	 parameter S=0, S1=1, S11=2, S110=3, B0=4, B1=5, B2=6, B3=7, Count=8, Wait=9;

	assign B3_next = state[B2];
	assign S_next = state[S]&~d | state[S1]&~d | state[S110]&~d | state[Wait]&ack;
	assign S1_next = state[S]&d;
	assign Count_next = state[B3] | state[Count]&~done_counting;
	assign Wait_next = state[Count]&done_counting | state[Wait]&~ack;

	assign done = state[Wait];
	assign counting = state[Count];
	assign shift_ena = |state[B3:B0];

endmodule

module stimulus_gen (
	input clk,
	output reg d, done_counting, ack,
	output reg [9:0] state,
	input tb_match
);
	bit failed = 0;
	bit fail_onehot = 0;

	always @(posedge clk, negedge clk)
		if (!tb_match)
			failed <= 1;

	initial begin
		{d, done_counting, ack} <= 3'h0;
		state <= 10'h0;

		repeat(300) @(posedge clk, negedge clk) begin
			{d, done_counting, ack} = $random;
			state <= 1<< ($unsigned($random) % 10);
		end

		@(posedge clk) fail_onehot <= failed;

		repeat(3000) @(posedge clk, negedge clk) begin
			{d, done_counting, ack} = $random;
			state <= $random;
		end

		@(posedge clk);
		if (!fail_onehot && failed) begin
			$display ("Hint: Your circuit passed when given only one-hot inputs, but not with random inputs.");
			$display ("Hint: Are you doing something more complicated than deriving state transition equations by inspection?\n");
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_B3_next;
		int errortime_B3_next;
		int errors_S_next;
		int errortime_S_next;
		int errors_S1_next;
		int errortime_S1_next;
		int errors_Count_next;
		int errortime_Count_next;
		int errors_Wait_next;
		int errortime_Wait_next;
		int errors_done;
		int errortime_done;
		int errors_counting;
		int errortime_counting;
		int errors_shift_ena;
		int errortime_shift_ena;

		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 done_counting;
	logic ack;
	logic [9:0] state;
	logic B3_next_ref;
	logic B3_next_dut;
	logic S_next_ref;
	logic S_next_dut;
	logic S1_next_ref;
	logic S1_next_dut;
	logic Count_next_ref;
	logic Count_next_dut;
	logic Wait_next_ref;
	logic Wait_next_dut;
	logic done_ref;
	logic done_dut;
	logic counting_ref;
	logic counting_dut;
	logic shift_ena_ref;
	logic shift_ena_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,d,done_counting,ack,state,B3_next_ref,B3_next_dut,S_next_ref,S_next_dut,S1_next_ref,S1_next_dut,Count_next_ref,Count_next_dut,Wait_next_ref,Wait_next_dut,done_ref,done_dut,counting_ref,counting_dut,shift_ena_ref,shift_ena_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.d,
		.done_counting,
		.ack,
		.state );
	reference_module good1 (
		.d,
		.done_counting,
		.ack,
		.state,
		.B3_next(B3_next_ref),
		.S_next(S_next_ref),
		.S1_next(S1_next_ref),
		.Count_next(Count_next_ref),
		.Wait_next(Wait_next_ref),
		.done(done_ref),
		.counting(counting_ref),
		.shift_ena(shift_ena_ref) );

	top_module top_module1 (
		.d,
		.done_counting,
		.ack,
		.state,
		.B3_next(B3_next_dut),
		.S_next(S_next_dut),
		.S1_next(S1_next_dut),
		.Count_next(Count_next_dut),
		.Wait_next(Wait_next_dut),
		.done(done_dut),
		.counting(counting_dut),
		.shift_ena(shift_ena_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_B3_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "B3_next", stats1.errors_B3_next, stats1.errortime_B3_next);
		else $display("Hint: Output '%s' has no mismatches.", "B3_next");
		if (stats1.errors_S_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "S_next", stats1.errors_S_next, stats1.errortime_S_next);
		else $display("Hint: Output '%s' has no mismatches.", "S_next");
		if (stats1.errors_S1_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "S1_next", stats1.errors_S1_next, stats1.errortime_S1_next);
		else $display("Hint: Output '%s' has no mismatches.", "S1_next");
		if (stats1.errors_Count_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "Count_next", stats1.errors_Count_next, stats1.errortime_Count_next);
		else $display("Hint: Output '%s' has no mismatches.", "Count_next");
		if (stats1.errors_Wait_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "Wait_next", stats1.errors_Wait_next, stats1.errortime_Wait_next);
		else $display("Hint: Output '%s' has no mismatches.", "Wait_next");
		if (stats1.errors_done) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "done", stats1.errors_done, stats1.errortime_done);
		else $display("Hint: Output '%s' has no mismatches.", "done");
		if (stats1.errors_counting) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "counting", stats1.errors_counting, stats1.errortime_counting);
		else $display("Hint: Output '%s' has no mismatches.", "counting");
		if (stats1.errors_shift_ena) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "shift_ena", stats1.errors_shift_ena, stats1.errortime_shift_ena);
		else $display("Hint: Output '%s' has no mismatches.", "shift_ena");

		$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 = ( { B3_next_ref, S_next_ref, S1_next_ref, Count_next_ref, Wait_next_ref, done_ref, counting_ref, shift_ena_ref } === ( { B3_next_ref, S_next_ref, S1_next_ref, Count_next_ref, Wait_next_ref, done_ref, counting_ref, shift_ena_ref } ^ { B3_next_dut, S_next_dut, S1_next_dut, Count_next_dut, Wait_next_dut, done_dut, counting_dut, shift_ena_dut } ^ { B3_next_ref, S_next_ref, S1_next_ref, Count_next_ref, Wait_next_ref, done_ref, counting_ref, shift_ena_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 (B3_next_ref !== ( B3_next_ref ^ B3_next_dut ^ B3_next_ref ))
		begin if (stats1.errors_B3_next == 0) stats1.errortime_B3_next = $time;
			stats1.errors_B3_next = stats1.errors_B3_next+1'b1; end
		if (S_next_ref !== ( S_next_ref ^ S_next_dut ^ S_next_ref ))
		begin if (stats1.errors_S_next == 0) stats1.errortime_S_next = $time;
			stats1.errors_S_next = stats1.errors_S_next+1'b1; end
		if (S1_next_ref !== ( S1_next_ref ^ S1_next_dut ^ S1_next_ref ))
		begin if (stats1.errors_S1_next == 0) stats1.errortime_S1_next = $time;
			stats1.errors_S1_next = stats1.errors_S1_next+1'b1; end
		if (Count_next_ref !== ( Count_next_ref ^ Count_next_dut ^ Count_next_ref ))
		begin if (stats1.errors_Count_next == 0) stats1.errortime_Count_next = $time;
			stats1.errors_Count_next = stats1.errors_Count_next+1'b1; end
		if (Wait_next_ref !== ( Wait_next_ref ^ Wait_next_dut ^ Wait_next_ref ))
		begin if (stats1.errors_Wait_next == 0) stats1.errortime_Wait_next = $time;
			stats1.errors_Wait_next = stats1.errors_Wait_next+1'b1; end
		if (done_ref !== ( done_ref ^ done_dut ^ done_ref ))
		begin if (stats1.errors_done == 0) stats1.errortime_done = $time;
			stats1.errors_done = stats1.errors_done+1'b1; end
		if (counting_ref !== ( counting_ref ^ counting_dut ^ counting_ref ))
		begin if (stats1.errors_counting == 0) stats1.errortime_counting = $time;
			stats1.errors_counting = stats1.errors_counting+1'b1; end
		if (shift_ena_ref !== ( shift_ena_ref ^ shift_ena_dut ^ shift_ena_ref ))
		begin if (stats1.errors_shift_ena == 0) stats1.errortime_shift_ena = $time;
			stats1.errors_shift_ena = stats1.errors_shift_ena+1'b1; end

	end
endmodule


Prompt:
module top_module(
    input d,
    input done_counting,
    input ack,
    input [9:0] state,    // 10-bit one-hot current state
    output B3_next,
    output S_next,
    output S1_next,
    output Count_next,
    output Wait_next,
    output done,
    output counting,
    output shift_ena
 );

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
    input d,
    input done_counting,
    input ack,
    input [9:0] state,    // 10-bit one-hot current state
    output B3_next,
    output S_next,
    output S1_next,
    output Count_next,
    output Wait_next,
    output done,
    output counting,
    output shift_ena
 );

	 parameter S=0, S1=1, S11=2, S110=3, B0=4, B1=5, B2=6, B3=7, Count=8, Wait=9;

	assign B3_next = state[B2];
	assign S_next = state[S]&~d | state[S1]&~d | state[S110]&~d | state[Wait]&ack;
	assign S1_next = state[S]&d;
	assign Count_next = state[B3] | state[Count]&~done_counting;
	assign Wait_next = state[Count]&done_counting | state[Wait]&~ack;

	assign done = state[Wait];
	assign counting = state[Count];
	assign shift_ena = |state[B3:B0];

endmodule

module stimulus_gen (
	input clk,
	output reg d, done_counting, ack,
	output reg [9:0] state,
	input tb_match
);
	bit failed = 0;
	bit fail_onehot = 0;

	always @(posedge clk, negedge clk)
		if (!tb_match)
			failed <= 1;

	initial begin
		{d, done_counting, ack} <= 3'h0;
		state <= 10'h0;

		repeat(300) @(posedge clk, negedge clk) begin
			{d, done_counting, ack} = $random;
			state <= 1<< ($unsigned($random) % 10);
		end

		@(posedge clk) fail_onehot <= failed;

		repeat(3000) @(posedge clk, negedge clk) begin
			{d, done_counting, ack} = $random;
			state <= $random;
		end

		@(posedge clk);
		if (!fail_onehot && failed) begin
			$display ("Hint: Your circuit passed when given only one-hot inputs, but not with random inputs.");
			$display ("Hint: Are you doing something more complicated than deriving state transition equations by inspection?\n");
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_B3_next;
		int errortime_B3_next;
		int errors_S_next;
		int errortime_S_next;
		int errors_S1_next;
		int errortime_S1_next;
		int errors_Count_next;
		int errortime_Count_next;
		int errors_Wait_next;
		int errortime_Wait_next;
		int errors_done;
		int errortime_done;
		int errors_counting;
		int errortime_counting;
		int errors_shift_ena;
		int errortime_shift_ena;

		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 done_counting;
	logic ack;
	logic [9:0] state;
	logic B3_next_ref;
	logic B3_next_dut;
	logic S_next_ref;
	logic S_next_dut;
	logic S1_next_ref;
	logic S1_next_dut;
	logic Count_next_ref;
	logic Count_next_dut;
	logic Wait_next_ref;
	logic Wait_next_dut;
	logic done_ref;
	logic done_dut;
	logic counting_ref;
	logic counting_dut;
	logic shift_ena_ref;
	logic shift_ena_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,d,done_counting,ack,state,B3_next_ref,B3_next_dut,S_next_ref,S_next_dut,S1_next_ref,S1_next_dut,Count_next_ref,Count_next_dut,Wait_next_ref,Wait_next_dut,done_ref,done_dut,counting_ref,counting_dut,shift_ena_ref,shift_ena_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.d,
		.done_counting,
		.ack,
		.state );
	reference_module good1 (
		.d,
		.done_counting,
		.ack,
		.state,
		.B3_next(B3_next_ref),
		.S_next(S_next_ref),
		.S1_next(S1_next_ref),
		.Count_next(Count_next_ref),
		.Wait_next(Wait_next_ref),
		.done(done_ref),
		.counting(counting_ref),
		.shift_ena(shift_ena_ref) );

	top_module top_module1 (
		.d,
		.done_counting,
		.ack,
		.state,
		.B3_next(B3_next_dut),
		.S_next(S_next_dut),
		.S1_next(S1_next_dut),
		.Count_next(Count_next_dut),
		.Wait_next(Wait_next_dut),
		.done(done_dut),
		.counting(counting_dut),
		.shift_ena(shift_ena_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_B3_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "B3_next", stats1.errors_B3_next, stats1.errortime_B3_next);
		else $display("Hint: Output '%s' has no mismatches.", "B3_next");
		if (stats1.errors_S_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "S_next", stats1.errors_S_next, stats1.errortime_S_next);
		else $display("Hint: Output '%s' has no mismatches.", "S_next");
		if (stats1.errors_S1_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "S1_next", stats1.errors_S1_next, stats1.errortime_S1_next);
		else $display("Hint: Output '%s' has no mismatches.", "S1_next");
		if (stats1.errors_Count_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "Count_next", stats1.errors_Count_next, stats1.errortime_Count_next);
		else $display("Hint: Output '%s' has no mismatches.", "Count_next");
		if (stats1.errors_Wait_next) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "Wait_next", stats1.errors_Wait_next, stats1.errortime_Wait_next);
		else $display("Hint: Output '%s' has no mismatches.", "Wait_next");
		if (stats1.errors_done) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "done", stats1.errors_done, stats1.errortime_done);
		else $display("Hint: Output '%s' has no mismatches.", "done");
		if (stats1.errors_counting) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "counting", stats1.errors_counting, stats1.errortime_counting);
		else $display("Hint: Output '%s' has no mismatches.", "counting");
		if (stats1.errors_shift_ena) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "shift_ena", stats1.errors_shift_ena, stats1.errortime_shift_ena);
		else $display("Hint: Output '%s' has no mismatches.", "shift_ena");

		$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 = ( { B3_next_ref, S_next_ref, S1_next_ref, Count_next_ref, Wait_next_ref, done_ref, counting_ref, shift_ena_ref } === ( { B3_next_ref, S_next_ref, S1_next_ref, Count_next_ref, Wait_next_ref, done_ref, counting_ref, shift_ena_ref } ^ { B3_next_dut, S_next_dut, S1_next_dut, Count_next_dut, Wait_next_dut, done_dut, counting_dut, shift_ena_dut } ^ { B3_next_ref, S_next_ref, S1_next_ref, Count_next_ref, Wait_next_ref, done_ref, counting_ref, shift_ena_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 (B3_next_ref !== ( B3_next_ref ^ B3_next_dut ^ B3_next_ref ))
		begin if (stats1.errors_B3_next == 0) stats1.errortime_B3_next = $time;
			stats1.errors_B3_next = stats1.errors_B3_next+1'b1; end
		if (S_next_ref !== ( S_next_ref ^ S_next_dut ^ S_next_ref ))
		begin if (stats1.errors_S_next == 0) stats1.errortime_S_next = $time;
			stats1.errors_S_next = stats1.errors_S_next+1'b1; end
		if (S1_next_ref !== ( S1_next_ref ^ S1_next_dut ^ S1_next_ref ))
		begin if (stats1.errors_S1_next == 0) stats1.errortime_S1_next = $time;
			stats1.errors_S1_next = stats1.errors_S1_next+1'b1; end
		if (Count_next_ref !== ( Count_next_ref ^ Count_next_dut ^ Count_next_ref ))
		begin if (stats1.errors_Count_next == 0) stats1.errortime_Count_next = $time;
			stats1.errors_Count_next = stats1.errors_Count_next+1'b1; end
		if (Wait_next_ref !== ( Wait_next_ref ^ Wait_next_dut ^ Wait_next_ref ))
		begin if (stats1.errors_Wait_next == 0) stats1.errortime_Wait_next = $time;
			stats1.errors_Wait_next = stats1.errors_Wait_next+1'b1; end
		if (done_ref !== ( done_ref ^ done_dut ^ done_ref ))
		begin if (stats1.errors_done == 0) stats1.errortime_done = $time;
			stats1.errors_done = stats1.errors_done+1'b1; end
		if (counting_ref !== ( counting_ref ^ counting_dut ^ counting_ref ))
		begin if (stats1.errors_counting == 0) stats1.errortime_counting = $time;
			stats1.errors_counting = stats1.errors_counting+1'b1; end
		if (shift_ena_ref !== ( shift_ena_ref ^ shift_ena_dut ^ shift_ena_ref ))
		begin if (stats1.errors_shift_ena == 0) stats1.errortime_shift_ena = $time;
			stats1.errors_shift_ena = stats1.errors_shift_ena+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	input data,
	output start_shifting);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	input data,
	output start_shifting);

	parameter S=0, S1=1, S11=2, S110=3, Done=4;

	reg [2:0] state, next;

	always_comb begin
		case (state)
			S: next = data ? S1: S;
			S1: next = data ? S11: S;
			S11: next = data ? S11 : S110;
			S110: next = data ? Done : S;
			Done: next = Done;
		endcase
	end

	always @(posedge clk)
		if (reset) state <= S;
		else state <= next;

	assign start_shifting = state == Done;

endmodule

module stimulus_gen (
	input clk,
	output reg reset, data,
	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

	wire [0:9] d = 10'b1110110011;

	initial begin
		reset <= 1;
		@(posedge clk) reset <= 0;
		data <= 1;
		repeat(2) @(posedge clk) ;
		data <= 0;
		@(posedge clk);
		data <= 1;
		@(posedge clk);
		data <= 0;

		wavedrom_start("Reset and sequence detect");
		reset_test();
		for (int i=0;i<10;i++) begin
			@(posedge clk) data <= d[i];
		end
		wavedrom_stop();
		repeat(600) @(posedge clk, negedge clk) begin
			reset <= !($random & 31);
			data <= $random;
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_start_shifting;
		int errortime_start_shifting;

		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 data;
	logic start_shifting_ref;
	logic start_shifting_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,data,start_shifting_ref,start_shifting_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.data );
	reference_module good1 (
		.clk,
		.reset,
		.data,
		.start_shifting(start_shifting_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.data,
		.start_shifting(start_shifting_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_start_shifting) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "start_shifting", stats1.errors_start_shifting, stats1.errortime_start_shifting);
		else $display("Hint: Output '%s' has no mismatches.", "start_shifting");

		$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 = ( { start_shifting_ref } === ( { start_shifting_ref } ^ { start_shifting_dut } ^ { start_shifting_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 (start_shifting_ref !== ( start_shifting_ref ^ start_shifting_dut ^ start_shifting_ref ))
		begin if (stats1.errors_start_shifting == 0) stats1.errortime_start_shifting = $time;
			stats1.errors_start_shifting = stats1.errors_start_shifting+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	input data,
	output start_shifting);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	input data,
	output start_shifting);

	parameter S=0, S1=1, S11=2, S110=3, Done=4;

	reg [2:0] state, next;

	always_comb begin
		case (state)
			S: next = data ? S1: S;
			S1: next = data ? S11: S;
			S11: next = data ? S11 : S110;
			S110: next = data ? Done : S;
			Done: next = Done;
		endcase
	end

	always @(posedge clk)
		if (reset) state <= S;
		else state <= next;

	assign start_shifting = state == Done;

endmodule

module stimulus_gen (
	input clk,
	output reg reset, data,
	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

	wire [0:9] d = 10'b1110110011;

	initial begin
		reset <= 1;
		@(posedge clk) reset <= 0;
		data <= 1;
		repeat(2) @(posedge clk) ;
		data <= 0;
		@(posedge clk);
		data <= 1;
		@(posedge clk);
		data <= 0;

		wavedrom_start("Reset and sequence detect");
		reset_test();
		for (int i=0;i<10;i++) begin
			@(posedge clk) data <= d[i];
		end
		wavedrom_stop();
		repeat(600) @(posedge clk, negedge clk) begin
			reset <= !($random & 31);
			data <= $random;
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_start_shifting;
		int errortime_start_shifting;

		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 data;
	logic start_shifting_ref;
	logic start_shifting_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,data,start_shifting_ref,start_shifting_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset,
		.data );
	reference_module good1 (
		.clk,
		.reset,
		.data,
		.start_shifting(start_shifting_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.data,
		.start_shifting(start_shifting_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_start_shifting) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "start_shifting", stats1.errors_start_shifting, stats1.errortime_start_shifting);
		else $display("Hint: Output '%s' has no mismatches.", "start_shifting");

		$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 = ( { start_shifting_ref } === ( { start_shifting_ref } ^ { start_shifting_dut } ^ { start_shifting_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 (start_shifting_ref !== ( start_shifting_ref ^ start_shifting_dut ^ start_shifting_ref ))
		begin if (stats1.errors_start_shifting == 0) stats1.errortime_start_shifting = $time;
			stats1.errors_start_shifting = stats1.errors_start_shifting+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	output shift_ena);

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

	parameter B0=0, B1=1, B2=2, B3=3, Done=4;

	reg [2:0] state, next;

	always_comb begin
		case (state)
			B0: next = B1;
			B1: next = B2;
			B2: next = B3;
			B3: next = Done;
			Done: next = Done;
		endcase
	end

	always @(posedge clk)
		if (reset) state <= B0;
		else state <= next;

	assign shift_ena = (state == B0 || state == B1 || state == B2 || state == B3);

endmodule

module stimulus_gen (
	input clk,
	output reg reset
);

	initial begin
		repeat(100) @(negedge clk) begin
			reset <= !($random & 31);
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_shift_ena;
		int errortime_shift_ena;

		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 shift_ena_ref;
	logic shift_ena_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,shift_ena_ref,shift_ena_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset );
	reference_module good1 (
		.clk,
		.reset,
		.shift_ena(shift_ena_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.shift_ena(shift_ena_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_shift_ena) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "shift_ena", stats1.errors_shift_ena, stats1.errortime_shift_ena);
		else $display("Hint: Output '%s' has no mismatches.", "shift_ena");

		$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 = ( { shift_ena_ref } === ( { shift_ena_ref } ^ { shift_ena_dut } ^ { shift_ena_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 (shift_ena_ref !== ( shift_ena_ref ^ shift_ena_dut ^ shift_ena_ref ))
		begin if (stats1.errors_shift_ena == 0) stats1.errortime_shift_ena = $time;
			stats1.errors_shift_ena = stats1.errors_shift_ena+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input reset,
	output shift_ena);

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

	parameter B0=0, B1=1, B2=2, B3=3, Done=4;

	reg [2:0] state, next;

	always_comb begin
		case (state)
			B0: next = B1;
			B1: next = B2;
			B2: next = B3;
			B3: next = Done;
			Done: next = Done;
		endcase
	end

	always @(posedge clk)
		if (reset) state <= B0;
		else state <= next;

	assign shift_ena = (state == B0 || state == B1 || state == B2 || state == B3);

endmodule

module stimulus_gen (
	input clk,
	output reg reset
);

	initial begin
		repeat(100) @(negedge clk) begin
			reset <= !($random & 31);
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_shift_ena;
		int errortime_shift_ena;

		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 shift_ena_ref;
	logic shift_ena_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,reset,shift_ena_ref,shift_ena_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.reset );
	reference_module good1 (
		.clk,
		.reset,
		.shift_ena(shift_ena_ref) );

	top_module top_module1 (
		.clk,
		.reset,
		.shift_ena(shift_ena_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_shift_ena) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "shift_ena", stats1.errors_shift_ena, stats1.errortime_shift_ena);
		else $display("Hint: Output '%s' has no mismatches.", "shift_ena");

		$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 = ( { shift_ena_ref } === ( { shift_ena_ref } ^ { shift_ena_dut } ^ { shift_ena_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 (shift_ena_ref !== ( shift_ena_ref ^ shift_ena_dut ^ shift_ena_ref ))
		begin if (stats1.errors_shift_ena == 0) stats1.errortime_shift_ena = $time;
			stats1.errors_shift_ena = stats1.errors_shift_ena+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input ring,
	input vibrate_mode,
	output ringer,
	output motor
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input ring,
	input vibrate_mode,
	output ringer,
	output motor
);

	assign ringer = ring & ~vibrate_mode;
	assign motor = ring & vibrate_mode;

endmodule

module stimulus_gen (
	input clk,
	output reg ring, vibrate_mode,
	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
		int count; count = 0;
		{vibrate_mode,ring} <= 1'b0;
		wavedrom_start();
		repeat(10) @(posedge clk)
			{vibrate_mode,ring} <= count++;
		wavedrom_stop();

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_ringer;
		int errortime_ringer;
		int errors_motor;
		int errortime_motor;

		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 ring;
	logic vibrate_mode;
	logic ringer_ref;
	logic ringer_dut;
	logic motor_ref;
	logic motor_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,ring,vibrate_mode,ringer_ref,ringer_dut,motor_ref,motor_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.ring,
		.vibrate_mode );
	reference_module good1 (
		.ring,
		.vibrate_mode,
		.ringer(ringer_ref),
		.motor(motor_ref) );

	top_module top_module1 (
		.ring,
		.vibrate_mode,
		.ringer(ringer_dut),
		.motor(motor_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_ringer) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "ringer", stats1.errors_ringer, stats1.errortime_ringer);
		else $display("Hint: Output '%s' has no mismatches.", "ringer");
		if (stats1.errors_motor) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "motor", stats1.errors_motor, stats1.errortime_motor);
		else $display("Hint: Output '%s' has no mismatches.", "motor");

		$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 = ( { ringer_ref, motor_ref } === ( { ringer_ref, motor_ref } ^ { ringer_dut, motor_dut } ^ { ringer_ref, motor_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 (ringer_ref !== ( ringer_ref ^ ringer_dut ^ ringer_ref ))
		begin if (stats1.errors_ringer == 0) stats1.errortime_ringer = $time;
			stats1.errors_ringer = stats1.errors_ringer+1'b1; end
		if (motor_ref !== ( motor_ref ^ motor_dut ^ motor_ref ))
		begin if (stats1.errors_motor == 0) stats1.errortime_motor = $time;
			stats1.errors_motor = stats1.errors_motor+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input ring,
	input vibrate_mode,
	output ringer,
	output motor
);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input ring,
	input vibrate_mode,
	output ringer,
	output motor
);

	assign ringer = ring & ~vibrate_mode;
	assign motor = ring & vibrate_mode;

endmodule

module stimulus_gen (
	input clk,
	output reg ring, vibrate_mode,
	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
		int count; count = 0;
		{vibrate_mode,ring} <= 1'b0;
		wavedrom_start();
		repeat(10) @(posedge clk)
			{vibrate_mode,ring} <= count++;
		wavedrom_stop();

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_ringer;
		int errortime_ringer;
		int errors_motor;
		int errortime_motor;

		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 ring;
	logic vibrate_mode;
	logic ringer_ref;
	logic ringer_dut;
	logic motor_ref;
	logic motor_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,ring,vibrate_mode,ringer_ref,ringer_dut,motor_ref,motor_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.ring,
		.vibrate_mode );
	reference_module good1 (
		.ring,
		.vibrate_mode,
		.ringer(ringer_ref),
		.motor(motor_ref) );

	top_module top_module1 (
		.ring,
		.vibrate_mode,
		.ringer(ringer_dut),
		.motor(motor_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_ringer) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "ringer", stats1.errors_ringer, stats1.errortime_ringer);
		else $display("Hint: Output '%s' has no mismatches.", "ringer");
		if (stats1.errors_motor) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "motor", stats1.errors_motor, stats1.errortime_motor);
		else $display("Hint: Output '%s' has no mismatches.", "motor");

		$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 = ( { ringer_ref, motor_ref } === ( { ringer_ref, motor_ref } ^ { ringer_dut, motor_dut } ^ { ringer_ref, motor_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 (ringer_ref !== ( ringer_ref ^ ringer_dut ^ ringer_ref ))
		begin if (stats1.errors_ringer == 0) stats1.errortime_ringer = $time;
			stats1.errors_ringer = stats1.errors_ringer+1'b1; end
		if (motor_ref !== ( motor_ref ^ motor_dut ^ motor_ref ))
		begin if (stats1.errors_motor == 0) stats1.errortime_motor = $time;
			stats1.errors_motor = stats1.errors_motor+1'b1; end

	end
endmodule


Prompt:
module top_module(
	input clk,
	input load,
	input [1:0] ena,
	input [99:0] data,
	output reg [99:0] q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input load,
	input [1:0] ena,
	input [99:0] data,
	output reg [99:0] q);

	always @(posedge clk) begin
		if (load)
			q <= data;
		else if (ena == 2'h1)
			q <= {q[0], q[99:1]};
		else if (ena == 2'h2)
			q <= {q[98:0], q[99]};
	end
endmodule

module stimulus_gen (
	input clk,
	output reg load,
	output reg[1:0] ena,
	output reg[99:0] data
);

	always @(posedge clk)
		data <= {$random,$random,$random,$random};

	initial begin
		load <= 1;
		@(posedge clk);
		@(posedge clk);
		@(posedge clk);
		repeat(4000) @(posedge clk, negedge clk) begin
			load <= !($random & 31);
			ena <= $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 load;
	logic [1:0] ena;
	logic [99:0] data;
	logic [99:0] q_ref;
	logic [99:0] q_dut;

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

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.load,
		.ena,
		.data );
	reference_module good1 (
		.clk,
		.load,
		.ena,
		.data,
		.q(q_ref) );

	top_module top_module1 (
		.clk,
		.load,
		.ena,
		.data,
		.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 load,
	input [1:0] ena,
	input [99:0] data,
	output reg [99:0] q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input load,
	input [1:0] ena,
	input [99:0] data,
	output reg [99:0] q);

	always @(posedge clk) begin
		if (load)
			q <= data;
		else if (ena == 2'h1)
			q <= {q[0], q[99:1]};
		else if (ena == 2'h2)
			q <= {q[98:0], q[99]};
	end
endmodule

module stimulus_gen (
	input clk,
	output reg load,
	output reg[1:0] ena,
	output reg[99:0] data
);

	always @(posedge clk)
		data <= {$random,$random,$random,$random};

	initial begin
		load <= 1;
		@(posedge clk);
		@(posedge clk);
		@(posedge clk);
		repeat(4000) @(posedge clk, negedge clk) begin
			load <= !($random & 31);
			ena <= $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 load;
	logic [1:0] ena;
	logic [99:0] data;
	logic [99:0] q_ref;
	logic [99:0] q_dut;

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

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.load,
		.ena,
		.data );
	reference_module good1 (
		.clk,
		.load,
		.ena,
		.data,
		.q(q_ref) );

	top_module top_module1 (
		.clk,
		.load,
		.ena,
		.data,
		.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 load,
	input [511:0] data,
	output reg [511:0] q);

`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input load,
	input [511:0] data,
	output reg [511:0] q);

	always @(posedge clk) begin
		if (load)
			q <= data;
		else begin
			q <=
			~((q[$bits(q)-1:1] & q[$bits(q)-1:0] & {q[$bits(q)-2:0], 1'b0}) |
			(~q[$bits(q)-1:1] & ~q[$bits(q)-1:0] & ~{q[$bits(q)-2:0], 1'b0}) |
			(q[$bits(q)-1:1] & ~q[$bits(q)-1:0] & ~{q[$bits(q)-2:0], 1'b0}) )
			;
		end
	end
endmodule

module stimulus_gen (
	input clk,
	output reg load,
	output reg[511:0] data,
	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
		data <= 0;
		data[0] <= 1'b1;
		load <= 1;
		@(posedge clk); wavedrom_start("Load q[511:0] = 1: See Hint.");
		@(posedge clk);
		@(posedge clk);
		load <= 0;
		repeat(10) @(posedge clk);
		wavedrom_stop();

		data <= 0;
		data[256] <= 1'b1;
		load <= 1;
		@(posedge clk);
		@(posedge clk);
		@(posedge clk);
		load <= 0;
		repeat(1000) @(posedge clk) begin
		end
		data <= 512'h4df;
		load <= 1;
		@(posedge clk);
		load <= 0;
		repeat(1000) @(posedge clk) begin
		end
		data <= $random;
		load <= 1;
		@(posedge clk);
		load <= 0;
		repeat(1000) @(posedge clk) begin
		end

		data <= 0;
		load <= 1;
		repeat (20) @(posedge clk);
		@(posedge clk) data <= 2;
		@(posedge clk) data <= 4;
		@(posedge clk) begin
			data <= 9;
			load <= 0;
		end
		@(posedge clk) data <= 12;
		repeat(100) @(posedge clk);

		#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 load;
	logic [511:0] data;
	logic [511:0] q_ref;
	logic [511:0] q_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.load,
		.data,
		.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