prompt:
module top_module (
	input a,
	input b,
	input c,
	input d,
	input e,
	output [24:0] out
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input a,
	input b,
	input c,
	input d,
	input e,
	output [24:0] out
);

	assign out = ~{ {5{a}}, {5{b}}, {5{c}}, {5{d}}, {5{e}} } ^ {5{a,b,c,d,e}};

endmodule

module stimulus_gen (
	input clk,
	output logic a, b, c, d, e
);

	initial begin
		repeat(100) @(posedge clk, negedge clk)
			{a,b,c,d,e} <= $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 a;
	logic b;
	logic c;
	logic d;
	logic e;
	logic [24:0] out_ref;
	logic [24:0] out_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,c,d,e,out_ref,out_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b,
		.c,
		.d,
		.e );
	reference_module good1 (
		.a,
		.b,
		.c,
		.d,
		.e,
		.out(out_ref) );

	top_module top_module1 (
		.a,
		.b,
		.c,
		.d,
		.e,
		.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

detail_description:
The input a, b, c, d, e are boolean signals.
The output out is a 25-bit vector.

The module computes the bitwise exclusive-or of the  25-bit vector ~{ {5{a}}, {5{b}}, {5{c}}, {5{d}}, {5{e}} } and the 25-bit vector {5{a,b,c,d,e}}. The first vector consists of 25 bits with value 1 if the corresponding input signal is 0, and consists of 25 bits with value 0 if the corresponding input signal is 1. The second vector consists of 25 bits with value 1 if the corresponding input signal is 1, and consists of 25 bits with value 0 if the corresponding input signal is 0.


prompt:
module top_module (
	input clk,
	input areset,
	input bump_left,
	input bump_right,
	output walk_left,
	output walk_right
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input areset,
	input bump_left,
	input bump_right,
	output walk_left,
	output walk_right
);
	parameter WL=0, WR=1;
	reg state;
	reg next;

    always_comb begin
		case (state)
			WL: next = bump_left ? WR : WL;
			WR: next = bump_right ? WL: WR;
		endcase
    end

    always @(posedge clk, posedge areset) begin
		if (areset) state <= WL;
        else state <= next;
	end

	assign walk_left = (state==WL);
	assign walk_right = (state==WR);

endmodule

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

	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'b1;
		{bump_right, bump_left} <= 3'h3;
		wavedrom_start("Asynchronous reset");
		reset_test(1);
		repeat(3) @(posedge clk);
		{bump_right, bump_left} <= 2;
		repeat(2) @(posedge clk);
		{bump_right, bump_left} <= 1;
		repeat(2) @(posedge clk);
		wavedrom_stop();

		@(posedge clk);
		repeat(200) @(posedge clk, negedge clk) begin
			{bump_right, bump_left} <= $random & $random;
			reset <= !($random & 31);
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_walk_left;
		int errortime_walk_left;
		int errors_walk_right;
		int errortime_walk_right;

		int clocks;
	} stats;

	stats stats1;

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

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

	logic areset;
	logic bump_left;
	logic bump_right;
	logic walk_left_ref;
	logic walk_left_dut;
	logic walk_right_ref;
	logic walk_right_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,areset,bump_left,bump_right,walk_left_ref,walk_left_dut,walk_right_ref,walk_right_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.areset,
		.bump_left,
		.bump_right );
	reference_module good1 (
		.clk,
		.areset,
		.bump_left,
		.bump_right,
		.walk_left(walk_left_ref),
		.walk_right(walk_right_ref) );

	top_module top_module1 (
		.clk,
		.areset,
		.bump_left,
		.bump_right,
		.walk_left(walk_left_dut),
		.walk_right(walk_right_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_walk_left) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "walk_left", stats1.errors_walk_left, stats1.errortime_walk_left);
		else $display("Hint: Output '%s' has no mismatches.", "walk_left");
		if (stats1.errors_walk_right) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "walk_right", stats1.errors_walk_right, stats1.errortime_walk_right);
		else $display("Hint: Output '%s' has no mismatches.", "walk_right");

		$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 = ( { walk_left_ref, walk_right_ref } === ( { walk_left_ref, walk_right_ref } ^ { walk_left_dut, walk_right_dut } ^ { walk_left_ref, walk_right_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 (walk_left_ref !== ( walk_left_ref ^ walk_left_dut ^ walk_left_ref ))
		begin if (stats1.errors_walk_left == 0) stats1.errortime_walk_left = $time;
			stats1.errors_walk_left = stats1.errors_walk_left+1'b1; end
		if (walk_right_ref !== ( walk_right_ref ^ walk_right_dut ^ walk_right_ref ))
		begin if (stats1.errors_walk_right == 0) stats1.errortime_walk_right = $time;
			stats1.errors_walk_right = stats1.errors_walk_right+1'b1; end

	end
endmodule

simple_description: This module implements a state machine that alternates between two states based on the bump_left and bump_right inputs, and assigns walk_left and walk_right outputs accordingly.

detail_description: This top Verilog module is a state machine that controls the walking direction of a robot. The module has 6 ports: clk, areset, bump_left, bump_right, walk_left, and walk_right. The clk port is an input port that is used to synchronize the state machine. The areset port is an input port that is used to reset the state machine to the initial state. The bump_left and bump_right ports are input ports that indicate whether the robot has bumped into an obstacle on the left or right side. The walk_left and walk_right ports are output ports that indicate the walking direction of the robot.  The module has two parameters, WL and WR, which represent the two states of the state machine. The state machine is implemented using a register, state, and a combinational logic block. The combinational logic block is used to determine the next state of the state machine based on the current state and the bump_left and bump_right inputs. If the current state is WL, the next state will be WR if the bump_left input is high, and WL if the bump_left input is low. Similarly, if the current state is WR, the next state will be WL if the bump_right input is high, and WR if the bump_right input is low.  The state machine is updated on the rising edge of the clk signal, and is reset to the initial state (WL) on the rising edge of the areset signal. The walk_left and walk_right outputs are assigned based on the current state of the state machine. If the state is WL, the walk_left output will be high and the walk_right output will be low. If the state is WR, the walk_left output will be low and the walk_right output will be high.


prompt:
module top_module (
	input a,
	input b,
	output q
);

canonical_solution:
	assign q = a&b;

endmodule

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input a,
	input b,
	output q
);

	assign q = a&b;

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		{a,b} <= 0;
		@(negedge clk) wavedrom_start("Unknown circuit");
			@(posedge clk) {a,b} <= 0;
			repeat(8) @(posedge clk) {a,b} <= {a,b} + 1;
		@(negedge clk) wavedrom_stop();

		repeat(100) @(posedge clk, negedge clk)
			{a,b} <= $urandom;
		$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 a;
	logic b;
	logic q_ref;
	logic q_dut;

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

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

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

	top_module top_module1 (
		.a,
		.b,
		.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

simple_description: This module assigns the output q to the logical AND of inputs a and b.

detail_description: This module implements a logic AND gate between two inputs a and b, and the output q is the result of the AND operation. The module has three ports, two inputs (a and b) and one output (q). The inputs a and b are connected to the AND gate, and the output q is the result of the AND operation between a and b. The AND gate performs a logical AND operation between the two inputs and produces a single output. The output q will be 1 if both inputs a and b are 1, and 0 otherwise.


prompt:
module top_module(
	input p1a,
	input p1b,
	input p1c,
	input p1d,
	input p1e,
	input p1f,
	output p1y,
	input p2a,
	input p2b,
	input p2c,
	input p2d,
	output p2y
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input p1a,
	input p1b,
	input p1c,
	input p1d,
	input p1e,
	input p1f,
	output p1y,
	input p2a,
	input p2b,
	input p2c,
	input p2d,
	output p2y
);

	assign p1y = &{p1a, p1b, p1c} | &{p1d, p1e, p1f};
	assign p2y = &{p2a, p2b} | &{p2c, p2d};

endmodule

module stimulus_gen (
	input clk,
	output reg p1a, p1b, p1c, p1d, p1e, p1f,
	output reg p2a, p2b, p2c, p2d,
	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;
		{p1a,p1b,p1c,p1d,p1e,p1f} <= 4'h0;
		{p2a,p2b,p2c,p2d} <= 4'h0;
		wavedrom_start();
		repeat(20) @(posedge clk) begin
			{p1a,p1b,p1c,p1d,p1e,p1f} <= {count[2:0], count[3:1]};
			{p2a,p2b,p2c,p2d} <= count;
			count = count + 1;
		end
		wavedrom_stop();

		repeat(400) @(posedge clk,negedge clk) begin
			{p1a,p1b,p1c,p1d,p2a,p2b,p2c,p2d} <= $random;
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_p1y;
		int errortime_p1y;
		int errors_p2y;
		int errortime_p2y;

		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 p1a;
	logic p1b;
	logic p1c;
	logic p1d;
	logic p1e;
	logic p1f;
	logic p2a;
	logic p2b;
	logic p2c;
	logic p2d;
	logic p1y_ref;
	logic p1y_dut;
	logic p2y_ref;
	logic p2y_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,p1a,p1b,p1c,p1d,p1e,p1f,p2a,p2b,p2c,p2d,p1y_ref,p1y_dut,p2y_ref,p2y_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.p1a,
		.p1b,
		.p1c,
		.p1d,
		.p1e,
		.p1f,
		.p2a,
		.p2b,
		.p2c,
		.p2d );
	reference_module good1 (
		.p1a,
		.p1b,
		.p1c,
		.p1d,
		.p1e,
		.p1f,
		.p2a,
		.p2b,
		.p2c,
		.p2d,
		.p1y(p1y_ref),
		.p2y(p2y_ref) );

	top_module top_module1 (
		.p1a,
		.p1b,
		.p1c,
		.p1d,
		.p1e,
		.p1f,
		.p2a,
		.p2b,
		.p2c,
		.p2d,
		.p1y(p1y_dut),
		.p2y(p2y_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_p1y) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "p1y", stats1.errors_p1y, stats1.errortime_p1y);
		else $display("Hint: Output '%s' has no mismatches.", "p1y");
		if (stats1.errors_p2y) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "p2y", stats1.errors_p2y, stats1.errortime_p2y);
		else $display("Hint: Output '%s' has no mismatches.", "p2y");

		$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 = ( { p1y_ref, p2y_ref } === ( { p1y_ref, p2y_ref } ^ { p1y_dut, p2y_dut } ^ { p1y_ref, p2y_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 (p1y_ref !== ( p1y_ref ^ p1y_dut ^ p1y_ref ))
		begin if (stats1.errors_p1y == 0) stats1.errortime_p1y = $time;
			stats1.errors_p1y = stats1.errors_p1y+1'b1; end
		if (p2y_ref !== ( p2y_ref ^ p2y_dut ^ p2y_ref ))
		begin if (stats1.errors_p2y == 0) stats1.errortime_p2y = $time;
			stats1.errors_p2y = stats1.errors_p2y+1'b1; end

	end
endmodule

simple_description: This module implements logic functions to generate outputs p1y and p2y from the given inputs.

detail_description: The top Verilog module is a combinational logic module that takes in 8 inputs and produces 2 outputs. The first output, p1y, is the result of a logical AND operation on the first three inputs (p1a, p1b, and p1c) and a logical OR operation on the last three inputs (p1d, p1e, and p1f). The second output, p2y, is the result of a logical AND operation on the first two inputs (p2a and p2b) and a logical OR operation on the last two inputs (p2c and p2d). The module does not contain any state elements, so the outputs are only dependent on the inputs.


prompt:
module top_module (
	input clk,
	input x,
	input [2:0] y,
	output reg Y0,
	output reg z
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input x,
	input [2:0] y,
	output reg Y0,
	output reg z
);

	always_comb begin
		case ({y[2:0], x})
			4'h0: Y0 = 0;
			4'h1: Y0 = 1;
			4'h2: Y0 = 1;
			4'h3: Y0 = 0;
			4'h4: Y0 = 0;
			4'h5: Y0 = 1;
			4'h6: Y0 = 1;
			4'h7: Y0 = 0;
			4'h8: Y0 = 1;
			4'h9: Y0 = 0;
			default: Y0 = 1'bx;
		endcase

		case (y[2:0])
			3'h0: z = 0;
			3'h1: z = 0;
			3'h2: z = 0;
			3'h3: z = 1;
			3'h4: z = 1;
			default: z = 1'bx;
		endcase
	end

endmodule

module stimulus_gen (
	input clk,
	output logic x,
	output logic [2:0] y
);

	initial begin
		repeat(200) @(posedge clk, negedge clk) begin
			y <= $random;
			x <= $random;
		end

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_Y0;
		int errortime_Y0;
		int errors_z;
		int errortime_z;

		int clocks;
	} stats;

	stats stats1;

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

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

	logic x;
	logic [2:0] y;
	logic Y0_ref;
	logic Y0_dut;
	logic z_ref;
	logic z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,clk,x,y,Y0_ref,Y0_dut,z_ref,z_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.x,
		.y );
	reference_module good1 (
		.clk,
		.x,
		.y,
		.Y0(Y0_ref),
		.z(z_ref) );

	top_module top_module1 (
		.clk,
		.x,
		.y,
		.Y0(Y0_dut),
		.z(z_dut) );

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

	final begin
		if (stats1.errors_Y0) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "Y0", stats1.errors_Y0, stats1.errortime_Y0);
		else $display("Hint: Output '%s' has no mismatches.", "Y0");
		if (stats1.errors_z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "z", stats1.errors_z, stats1.errortime_z);
		else $display("Hint: Output '%s' has no mismatches.", "z");

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

	// Verification: XORs on the right makes any X in good_vector match anything, but X in dut_vector will only match X.
	assign tb_match = ( { Y0_ref, z_ref } === ( { Y0_ref, z_ref } ^ { Y0_dut, z_dut } ^ { Y0_ref, z_ref } ) );
	// Use explicit sensitivity list here. @(*) causes NetProc::nex_input() to be called when trying to compute
	// the sensitivity list of the @(strobe) process, which isn't implemented.
	always @(posedge clk, negedge clk) begin

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (Y0_ref !== ( Y0_ref ^ Y0_dut ^ Y0_ref ))
		begin if (stats1.errors_Y0 == 0) stats1.errortime_Y0 = $time;
			stats1.errors_Y0 = stats1.errors_Y0+1'b1; end
		if (z_ref !== ( z_ref ^ z_dut ^ z_ref ))
		begin if (stats1.errors_z == 0) stats1.errortime_z = $time;
			stats1.errors_z = stats1.errors_z+1'b1; end

	end
endmodule

detail_description:
	In this module, x and y connect with top_module, which is a 3-bit vector.
	Y0 and z are two output ports.
	Inside the always_comb, it defines Y0 using a case statement.
	When {y[2:0],x}=4'h0, the output of Y0 is 0;
	When {y[2:0],x}=4'h1, the output of Y0 is 1;
	When {y[2:0],x}=4'h2, the output of Y0 is 1;
	When {y[2:0],x}=4'h3, the output of Y0 is 0;
	When {y[2:0],x}=4'h4, the output of Y0 is 0;
	When {y[2:0],x}=4'h5, the output of Y0 is 1;
	When {y[2:0],x}=4'h6, the output of Y0 is 1;
	When {y[2:0],x}=4'h7, the output of Y0 is 0;
	When {y[2:0],x}=4'h8, the output of Y0 is 1;
	When {y[2:0],x}=4'h9, the output of Y0 is 0;
	When {y[2:0],x} does not match any one of the above conditions, the output of Y0 is x;

	Inside the always_comb, it defines z using a case statement.
	When y[2:0]=3'h0, the output of z is 0;
	When y[2:0]=3'h1, the output of z is 0;
	When y[2:0]=3'h2, the output of z is 0;
	When y[2:0]=3'h3, the output of z is 1;
	When y[2:0]=3'h4, the output of z is 1;
	When y[2:0] does not match any one of the above conditions, the output of z is x;


prompt:
module top_module (
	input in1,
	input in2,
	output logic out
);

canonical_solution:
	assign out = ~(in1 | in2);
endmodule

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input in1,
	input in2,
	output logic out
);

	assign out = ~(in1 | in2);
endmodule

module stimulus_gen (
	input clk,
	output logic in1, in2
);

	initial begin
		repeat(100) @(posedge clk, negedge clk) begin
			{in1, in2} <= $random;
		end

		#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 in1;
	logic in2;
	logic out_ref;
	logic out_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,in1,in2,out_ref,out_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.in1,
		.in2 );
	reference_module good1 (
		.in1,
		.in2,
		.out(out_ref) );

	top_module top_module1 (
		.in1,
		.in2,
		.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

simple_description: This module takes two inputs and outputs the logical NOT of their OR.

detail_description: This Verilog module is a combinational logic module that takes two input signals, in1 and in2, and produces one output signal, out. The output signal is the logical negation of the logical OR of the two input signals. This means that the output signal will be high (1) if both input signals are low (0), and will be low (0) if either of the input signals is high (1). This module is useful for implementing logic functions such as a NAND gate or a NOR gate.


prompt:
module top_module (
	input a,
	input b,
	input c,
	output w,
	output x,
	output y,
	output z  );

canonical_solution:
	assign {w,x,y,z} = {a,b,b,c};

endmodule

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input a,
	input b,
	input c,
	output w,
	output x,
	output y,
	output z  );

	assign {w,x,y,z} = {a,b,b,c};

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

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

	initial begin
		@(negedge clk) wavedrom_start();
			repeat(8) @(posedge clk);
		@(negedge clk) wavedrom_stop();
		repeat(100) @(negedge clk);
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_w;
		int errortime_w;
		int errors_x;
		int errortime_x;
		int errors_y;
		int errortime_y;
		int errors_z;
		int errortime_z;

		int clocks;
	} stats;

	stats stats1;

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

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

	logic a;
	logic b;
	logic c;
	logic w_ref;
	logic w_dut;
	logic x_ref;
	logic x_dut;
	logic y_ref;
	logic y_dut;
	logic z_ref;
	logic z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,c,w_ref,w_dut,x_ref,x_dut,y_ref,y_dut,z_ref,z_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b,
		.c );
	reference_module good1 (
		.a,
		.b,
		.c,
		.w(w_ref),
		.x(x_ref),
		.y(y_ref),
		.z(z_ref) );

	top_module top_module1 (
		.a,
		.b,
		.c,
		.w(w_dut),
		.x(x_dut),
		.y(y_dut),
		.z(z_dut) );

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

	final begin
		if (stats1.errors_w) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "w", stats1.errors_w, stats1.errortime_w);
		else $display("Hint: Output '%s' has no mismatches.", "w");
		if (stats1.errors_x) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "x", stats1.errors_x, stats1.errortime_x);
		else $display("Hint: Output '%s' has no mismatches.", "x");
		if (stats1.errors_y) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "y", stats1.errors_y, stats1.errortime_y);
		else $display("Hint: Output '%s' has no mismatches.", "y");
		if (stats1.errors_z) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "z", stats1.errors_z, stats1.errortime_z);
		else $display("Hint: Output '%s' has no mismatches.", "z");

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

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

		stats1.clocks++;
		if (!tb_match) begin
			if (stats1.errors == 0) stats1.errortime = $time;
			stats1.errors++;
		end
		if (w_ref !== ( w_ref ^ w_dut ^ w_ref ))
		begin if (stats1.errors_w == 0) stats1.errortime_w = $time;
			stats1.errors_w = stats1.errors_w+1'b1; end
		if (x_ref !== ( x_ref ^ x_dut ^ x_ref ))
		begin if (stats1.errors_x == 0) stats1.errortime_x = $time;
			stats1.errors_x = stats1.errors_x+1'b1; end
		if (y_ref !== ( y_ref ^ y_dut ^ y_ref ))
		begin if (stats1.errors_y == 0) stats1.errortime_y = $time;
			stats1.errors_y = stats1.errors_y+1'b1; end
		if (z_ref !== ( z_ref ^ z_dut ^ z_ref ))
		begin if (stats1.errors_z == 0) stats1.errortime_z = $time;
			stats1.errors_z = stats1.errors_z+1'b1; end

	end
endmodule

simple_description: This module assigns the outputs w,x,y,z to the inputs a,b,b,c respectively.

detail_description: This Verilog module is a simple combinational logic module that assigns the values of the inputs a, b, and c to the outputs w, x, y, and z. Specifically, the output w is assigned the value of input a, the output x is assigned the value of input b, the output y is assigned the value of input b, and the output z is assigned the value of input c. This module does not contain any state transitions or logic descriptions, as it is a simple combinational logic module.


prompt:
module top_module (
	input clk,
	input d,
	input ar,
	output logic q
);

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

	always@(posedge clk or posedge ar) begin
		if (ar)
			q <= 0;
		else
			q <= d;
	end

endmodule

module stimulus_gen (
	input clk,
	output logic d, ar
);

	initial begin
		repeat(100) @(posedge clk, negedge clk) begin
			{d,ar} <= $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 d;
	logic ar;
	logic q_ref;
	logic q_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.d,
		.ar,
		.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

simple_description: This module synchronizes the input signal d to the clock signal clk, and resets the output signal q when the asynchronous reset signal ar is asserted.

detail_description: This Verilog module is a simple register with an asynchronous reset. It has three inputs, clk, d, and ar, and one output, q. The clk input is the clock signal which is used to synchronize the register. The d input is the data that will be stored in the register. The ar input is the asynchronous reset signal which will reset the register to 0. The q output is the output of the register which will be the value stored in the register.  The module has an always block which is triggered on the rising edge of the clock signal or the asynchronous reset signal. When the asynchronous reset signal is triggered, the output q is set to 0. Otherwise, when the clock signal is triggered, the output q is set to the value of the data input d. This allows the register to store the value of the data input d until the asynchronous reset signal is triggered.


prompt:
module top_module (
	input [2:0] sel,
	input [3:0] data0,
	input [3:0] data1,
	input [3:0] data2,
	input [3:0] data3,
	input [3:0] data4,
	input [3:0] data5,
	output reg [3:0] out
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [2:0] sel,
	input [3:0] data0,
	input [3:0] data1,
	input [3:0] data2,
	input [3:0] data3,
	input [3:0] data4,
	input [3:0] data5,
	output reg [3:0] out
);

	always @(*) begin
		case (sel)
			3'h0: out = data0;
			3'h1: out = data1;
			3'h2: out = data2;
			3'h3: out = data3;
			3'h4: out = data4;
			3'h5: out = data5;
			default: out = 4'b0;
		endcase
	end

endmodule

module stimulus_gen (
	input clk,
	output logic [2:0] sel,
	output logic [3:0] data0,
	output logic [3:0] data1,
	output logic [3:0] data2,
	output logic [3:0] data3,
	output logic [3:0] data4,
	output logic [3:0] data5,
	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
		data0 <= 4'ha;
		data1 <= 4'hb;
		data2 <= 4'hc;
		data3 <= 4'hd;
		data4 <= 4'he;
		data5 <= 4'hf;
		{sel} <= 3'b111;
		@(negedge clk) wavedrom_start("<b>Sel</b> chooses one of the data inputs");
			repeat(8) @(posedge clk) sel <= sel + 1;
		@(negedge clk) wavedrom_stop();

		repeat(100) @(posedge clk, negedge clk) begin
			{data0, data1, data2, data3} <= $urandom;
			{data4, data5, sel} <= $urandom;
		end
		$finish;
	end

endmodule

module tb();

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

		int clocks;
	} stats;

	stats stats1;

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

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

	logic [2:0] sel;
	logic [3:0] data0;
	logic [3:0] data1;
	logic [3:0] data2;
	logic [3:0] data3;
	logic [3:0] data4;
	logic [3:0] data5;
	logic [3:0] out_ref;
	logic [3:0] out_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,sel,data0,data1,data2,data3,data4,data5,out_ref,out_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.sel,
		.data0,
		.data1,
		.data2,
		.data3,
		.data4,
		.data5 );
	reference_module good1 (
		.sel,
		.data0,
		.data1,
		.data2,
		.data3,
		.data4,
		.data5,
		.out(out_ref) );

	top_module top_module1 (
		.sel,
		.data0,
		.data1,
		.data2,
		.data3,
		.data4,
		.data5,
		.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

simple_description: This module selects one of 6 inputs based on the 3-bit selector and outputs the selected data.

detail_description: This Verilog module is a multiplexer which takes in 6 data inputs (data0-data5) and a selection input (sel) and outputs a single data output (out). The selection input (sel) is a 3-bit number which determines which of the 6 data inputs is selected as the output. If the selection input is 0, then the output will be the data0 input. If the selection input is 1, then the output will be the data1 input, and so on. If the selection input is any other value, then the output will be 0. The output is a 4-bit register which will hold the value of the selected data input until the selection input is changed.


task_id: timer

prompt:
module top_module(
	input clk,
	input load,
	input [9:0] data,
	output tc
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input load,
	input [9:0] data,
	output tc
);
	logic [9:0] count_value;

	always @(posedge clk)
		if(load) count_value <= data;
		else if(count_value != 0) count_value <= count_value - 1;

	assign tc = count_value == 0;

endmodule

module stimulus_gen(
	input clk,
	output logic load,
	output logic [9:0] data,
	input tb_match,
	output reg[511:0] wavedrom_title,
	output reg wavedrom_enable,
	output int wavedrom_hide_after_time
);

// 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
		load <= 1'b0;
		wavedrom_start("Count 3, then 10 cycles");
			@(posedge clk) {data, load} <= {10'd3, 1'b1};
			@(posedge clk) {data, load} <= {10'hx, 1'b0};
			@(posedge clk) load <= 0;
			@(posedge clk) load <= 0;
			@(posedge clk) load <= 0;
			@(posedge clk) {data, load} <= {10'd10, 1'b1};
			@(posedge clk) {data, load} <= {10'hx, 1'b0};
			repeat(12) @(posedge clk);
		wavedrom_stop();

		@(posedge clk) {load, data} <= {1'b1, 10'h10};
		@(posedge clk) {load, data} <= {1'b0, 10'h10};
		@(posedge clk) {load, data} <= {1'b1, 10'h0};   // Load 0
		@(posedge clk) {load, data} <= {1'b1, 10'h3ff}; // Load 1023
		@(posedge clk) {load, data} <= {1'b0, 10'h0};
		repeat(1040) @(posedge clk);

		repeat(2500) @(posedge clk) begin
			load <= !($urandom & 10'hf);
			data <= $urandom_range(0,32);
		end

		#1 $finish;
	end

endmodule
module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_tc;
		int errortime_tc;

		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 [9:0] data;
	logic tc_ref;
	logic tc_dut;

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

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.load,
		.data );
	reference_module good1 (
		.clk,
		.load,
		.data,
		.tc(tc_ref) );

	top_module top_module1 (
		.clk,
		.load,
		.data,
		.tc(tc_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_tc) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "tc", stats1.errors_tc, stats1.errortime_tc);
		else $display("Hint: Output '%s' has no mismatches.", "tc");

		$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 = ( { tc_ref } === ( { tc_ref } ^ { tc_dut } ^ { tc_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 (tc_ref !== ( tc_ref ^ tc_dut ^ tc_ref ))
		begin if (stats1.errors_tc == 0) stats1.errortime_tc = $time;
			stats1.errors_tc = stats1.errors_tc+1'b1; end

	end
endmodule

simple_description: This module counts down from an initial value loaded from the data input and outputs a signal when the count reaches 0.

detail_description: This Verilog module is a simple counter. It has four ports: clk, load, data, and tc. The clk port is an input port that is used to clock the counter. The load port is an input port that is used to determine whether the counter should be loaded with a new value. The data port is an input port that is used to provide the new value to the counter when the load port is asserted. The tc port is an output port that is used to indicate when the counter has reached 0.  The module contains an always block that is triggered on the rising edge of the clk port. Inside the always block, there is an if-else statement that is used to control the counter. If the load port is asserted, then the counter is loaded with the value from the data port. Otherwise, if the counter is not already at 0, then the counter is decremented by 1.  Finally, the tc port is assigned to the result of the comparison between the counter value and 0. When the counter value is 0, the tc port is asserted.


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

test:
`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

detail_description: This top Verilog module is a state machine that controls the state of the data within a shift register. The module has 4 ports: a clock (clk), a reset (reset), a data input (data), and an output (start_shifting). The module has 5 states: S, S1, S11, S110, and Done. The module is implemented using a register, state, and a combinational logic block. The combinational logic block is used to determine the next state of the state machine based on the current state and the data input. If the current state is S, and the data input is high, then the next state will be S1. If the data input is low, the next state will be S. If the current state is S1, and the data input is high, the next state will be S11. If the data input is low, the next state will be S. If the current state is S11, and the data input is high, the next state will be S11. If the data input is low, the next state will be S110. If the current state is S110, and the data input is high, the next state will be Done. If the data input is low, the next state will be S. If the current state is Done, the next state will be Done.  The state machine is updated on the rising edge of the clk signal, and is reset to the initial state (S) on the rising edge of the reset signal. The output of the state machine is assigned based on the current state of the state machine. The output will be high if the state is Done, and low otherwise.


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

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

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

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

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

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

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

	endtask

	initial begin
		reset <= 1;
		d <= $random;
		wavedrom_start("Synchronous active-high reset");
		reset_test();
		repeat(10) @(negedge clk)
			d <= $random;
		wavedrom_stop();

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

		#1 $finish;
	end

endmodule

module tb();

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

		int clocks;
	} stats;

	stats stats1;

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

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

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

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

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

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

	top_module top_module1 (
		.clk,
		.d,
		.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

simple_description: This module takes in a clock signal, 8-bit data, and a reset signal, and outputs a 8-bit register that is reset to 0 when reset is asserted and is set to the data when reset is deasserted.

detail_description: This Verilog module is a simple 8-bit register that is triggered by a clock signal. It has four ports: a clock (clk) input, a data (d) input, a reset input, and a data (q) output. The clock input is used to synchronize the register, the data input is used to set the value of the register, the reset input is used to reset the register to 0, and the data output is used to read the value of the register.   The module is implemented using an always block that is triggered by the rising edge of the clock signal. When the reset input is high, the output q is set to 0. Otherwise, the output q is set to the value of the data input d. This allows the register to store the value of the data input until it is reset or a new value is written.


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

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

	reg [7:0] d_last;

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

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

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

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

endmodule

module tb();

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

		int clocks;
	} stats;

	stats stats1;

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

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

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

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

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

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

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

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

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

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

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

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

	end
endmodule

simple_description: This module detects any edge on the input signal 'in' and stores it in the output signal 'anyedge'.

detail_description: This Verilog module is used to detect any edge on the input signal. The module has three ports: clk, in, and anyedge. The clk port is an input signal that is used to control the timing of the module. The in port is an 8-bit input signal that is used as the signal to detect edges on. The anyedge port is an 8-bit output signal that is used to indicate if an edge was detected on the in signal.  The module contains a register d_last that is used to store the previous value of the in signal. The always block is used to detect any edge on the in signal. Inside the always block, the d_last register is updated with the current value of the in signal. The anyedge output signal is then calculated by performing an exclusive-or (XOR) operation between the current value of the in signal and the value stored in the d_last register. If the values are different, then an edge was detected and the anyedge output signal will be set to 1. If the values are the same, then no edge was detected and the anyedge output signal will be set to 0.


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

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

	always @(posedge clk)
		if (reset || q == 10)
			q <= 1;
		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 and counting.");
		reset_test();
		repeat(12) @(posedge clk);
		wavedrom_stop();
		@(posedge clk);

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

endmodule

module tb();

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

		int clocks;
	} stats;

	stats stats1;

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

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

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

simple_description: This module is a 4-bit counter that increments its output (q) on the rising edge of the clock (clk) and resets to 1 when the reset signal is asserted or q reaches 10.

detail_description: This top Verilog module is a simple counter that increments its output q by one every clock cycle. It has 3 inputs, a clock (clk), a reset signal (reset), and an output register (q). The output register is a 4-bit register, meaning it can store values from 0 to 15.   The module is triggered on the rising edge of the clock signal. When the reset signal is active, the output register is set to 1. If the reset signal is not active, the output register is incremented by one. When the output register reaches 10 (1010 in binary), it is reset to 1. This process is repeated every clock cycle.


prompt:
module top_module (
	input clk,
	input a,
	output reg [2:0] q
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input a,
	output reg [2:0] q
);

	always @(posedge clk)
		if (a)
			q <= 4;
		else if (q == 6)
			q <= 0;
		else
			q <= q + 1'b1;

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		a <= 1;
		@(negedge clk) {a} <= 1;
		@(negedge clk) wavedrom_start("Unknown circuit");
			repeat(2) @(posedge clk);
			@(posedge clk) {a} <= 0;
			repeat(11) @(posedge clk);
			@(negedge clk) a <= 1;
			repeat(5) @(posedge clk, negedge clk);
			a <= 0;
			repeat(4) @(posedge clk);
		wavedrom_stop();

		repeat(200) @(posedge clk, negedge clk)
			a <= &((5)'($urandom));
		$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 a;
	logic [2:0] q_ref;
	logic [2:0] q_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.a,
		.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

detail_description:
The top Verilog module is a Mealy machine with two inputs (clk and a) and one output (q).
The output q is a 3-bit value.
The input a is an activity signal.
When a is 1, q is set to 4.
When a is 0 and q is 6, q is set to 0.
When a is 0 and q is not 6, q is increased by 1.


prompt:
module top_module(
	input clk,
	input reset,
	output reg [4:0] q);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module(
	input clk,
	input reset,
	output reg [4:0] q);

	logic [4:0] q_next;
	always @(q) begin
		q_next = q[4:1];
		q_next[4] = q[0];
		q_next[2] ^= q[0];
	end

	always @(posedge clk) begin
		if (reset)
			q <= 5'h1;
		else
			q <= q_next;
	end
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;
		@(negedge clk);
		wavedrom_start();
			reset_test();
			repeat(8) @(posedge clk);
		@(negedge clk);
		wavedrom_stop();
		repeat(400) @(posedge clk, negedge clk) begin
			reset <= !($random & 31);
		end
		@(posedge clk) reset <= 1'b0;
		repeat(2000) @(posedge clk);
		reset <= 1'b1;
		repeat(5) @(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 [4:0] q_ref;
	logic [4:0] 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

detail_description:
The top module has 3 inputs and 1 output, where the inputs are clk, reset, and output is q.
The module has 2 always blocks to define the state transition of q and the logic description.
The state transitions are defined in the first always block, which is triggered when q changes.
In the first always block, q_next is assigned with q[4:1], which is the value of q except the LSB bit.
Then, q_next[4] is assigned with q[0], which is the LSB bit.
Lastly, q_next[2] is xored with q[0].
The second always block is triggered at positive edge of clk.
If reset is active, q is assigned with 5'h1, which is the reset value.
If reset is inactive, q is assigned with q_next, which is the state transition.
The port connections of instantiated modules are shown above.
The module takes clk, reset, and q as input.
q is a 5 bit output, which is assigned with 5'h1 at reset and q_next at positive edge of clk.


prompt:
module top_module (
	input do_sub,
	input [7:0] a,
	input [7:0] b,
	output reg [7:0] out,
	output reg result_is_zero
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input do_sub,
	input [7:0] a,
	input [7:0] b,
	output reg [7:0] out,
	output reg result_is_zero
);

	always @(*) begin
		case (do_sub)
			0: out = a + b;
			1: out = a - b;
		endcase
		result_is_zero = (out == 0);
	end

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		{a, b} <= 16'haabb;
		do_sub <= 0;
		@(negedge clk) wavedrom_start("");
			@(posedge clk, negedge clk) do_sub <= 0;
			@(posedge clk, negedge clk) do_sub <= 0;
			@(posedge clk, negedge clk) do_sub <= 1;
			@(posedge clk, negedge clk) do_sub <= 1;

			@(posedge clk, negedge clk) {a, b} <= 16'h0303; do_sub <= 1'b0;
			@(posedge clk, negedge clk) do_sub <= 0;
			@(posedge clk, negedge clk) do_sub <= 1;
			@(posedge clk, negedge clk) {a, b} <= 16'h0304; do_sub <= 1'b0;
			@(posedge clk, negedge clk) do_sub <= 0;
			@(posedge clk, negedge clk) do_sub <= 1;
			@(posedge clk, negedge clk) {a, b} <= 16'hfd03; do_sub <= 1'b0;
			@(posedge clk, negedge clk) do_sub <= 0;
			@(posedge clk, negedge clk) do_sub <= 1;
			@(posedge clk, negedge clk) {a, b} <= 16'hfd04; do_sub <= 1'b0;
			@(posedge clk, negedge clk) do_sub <= 0;
			@(posedge clk, negedge clk) do_sub <= 1;
		wavedrom_stop();

		repeat(100) @(posedge clk, negedge clk) begin
			{a,b, do_sub} <= $urandom;
		end

		$finish;
	end

endmodule

module tb();

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

		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 do_sub;
	logic [7:0] a;
	logic [7:0] b;
	logic [7:0] out_ref;
	logic [7:0] out_dut;
	logic result_is_zero_ref;
	logic result_is_zero_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,do_sub,a,b,out_ref,out_dut,result_is_zero_ref,result_is_zero_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.do_sub,
		.a,
		.b );
	reference_module good1 (
		.do_sub,
		.a,
		.b,
		.out(out_ref),
		.result_is_zero(result_is_zero_ref) );

	top_module top_module1 (
		.do_sub,
		.a,
		.b,
		.out(out_dut),
		.result_is_zero(result_is_zero_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");
		if (stats1.errors_result_is_zero) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "result_is_zero", stats1.errors_result_is_zero, stats1.errortime_result_is_zero);
		else $display("Hint: Output '%s' has no mismatches.", "result_is_zero");

		$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, result_is_zero_ref } === ( { out_ref, result_is_zero_ref } ^ { out_dut, result_is_zero_dut } ^ { out_ref, result_is_zero_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
		if (result_is_zero_ref !== ( result_is_zero_ref ^ result_is_zero_dut ^ result_is_zero_ref ))
		begin if (stats1.errors_result_is_zero == 0) stats1.errortime_result_is_zero = $time;
			stats1.errors_result_is_zero = stats1.errors_result_is_zero+1'b1; end

	end
endmodule

simple_description: This module takes two 8-bit inputs, a and b, and depending on the value of do_sub, either adds or subtracts them to produce an 8-bit output, out, and a result_is_zero flag.

detail_description: This Verilog module is a top-level module that implements basic arithmetic operations. It has two inputs, do_sub and a and b, and two outputs, out and result_is_zero. The do_sub input is a single bit signal that determines whether the module should perform an addition or a subtraction. The a and b inputs are 8-bit signals that represent the two operands. The out output is an 8-bit signal that contains the result of the operation, and the result_is_zero output is a single bit signal that is set to 1 if the result of the operation is 0.  The module contains an always block that is triggered on any change in the inputs. Inside the always block, a case statement is used to determine which operation to perform based on the do_sub input. If do_sub is 0, then the module performs an addition, and if do_sub is 1, then the module performs a subtraction. The result of the operation is stored in the out output. The result_is_zero output is then set to 1 if the result of the operation is 0, and 0 otherwise.


prompt:
module top_module (
	input [4:1] x,
	output logic f
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [4:1] x,
	output logic f
);

	always_comb begin
		case (x)
			4'h0: f = 1'bx;
			4'h1: f = 1'bx;
			4'h2: f = 0;
			4'h3: f = 1'bx;
			4'h4: f = 1;
			4'h5: f = 1'bx;
			4'h6: f = 1;
			4'h7: f = 0;
			4'h8: f = 0;
			4'h9: f = 0;
			4'ha: f = 1'bx;
			4'hb: f = 1;
			4'hc: f = 1;
			4'hd: f = 1'bx;
			4'he: f = 1;
			4'hf: f = 1'bx;
		endcase
	end

endmodule

module stimulus_gen (
	input clk,
	output logic [4:1] x
);

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

		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_f;
		int errortime_f;

		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 [4:1] x;
	logic f_ref;
	logic f_dut;

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

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.x );
	reference_module good1 (
		.x,
		.f(f_ref) );

	top_module top_module1 (
		.x,
		.f(f_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_f) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "f", stats1.errors_f, stats1.errortime_f);
		else $display("Hint: Output '%s' has no mismatches.", "f");

		$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 = ( { f_ref } === ( { f_ref } ^ { f_dut } ^ { f_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 (f_ref !== ( f_ref ^ f_dut ^ f_ref ))
		begin if (stats1.errors_f == 0) stats1.errortime_f = $time;
			stats1.errors_f = stats1.errors_f+1'b1; end

	end
endmodule

detail_description:
When the input is 4'h0 then the output is 1'bx.
When the input is 4'h1 then the output is 1'bx.
When the input is 4'h2 then the output is 0.
When the input is 4'h3 then the output is 1'bx.
When the input is 4'h4 then the output is 1.
When the input is 4'h5 then the output is 1'bx.
When the input is 4'h6 then the output is 1.
When the input is 4'h7 then the output is 0.
When the input is 4'h8 then the output is 0.
When the input is 4'h9 then the output is 0.
When the input is 4'ha then the output is 1'bx.
When the input is 4'hb then the output is 1.
When the input is 4'hc then the output is 1.
When the input is 4'hd then the output is 1'bx.
When the input is 4'he then the output is 1.
When the input is 4'hf then the output is 1'bx.


prompt:
module top_module (
	input [7:0] code,
	output reg [3:0] out,
	output reg valid
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [7:0] code,
	output reg [3:0] out,
	output reg valid
);
//	uhh.. make a case statement: maps scancode to 0-9, but accidentally infer a latch?
//  and have one of the entries be wrong? (duplicate case, using different base!)
	always @(*) begin
		out = 0;
		valid = 1;
		case (code)
			8'h45: out = 0;
			8'h16: out = 1;
			8'h1e: out = 2;
			8'h26: out = 3;
			8'h25: out = 4;
			8'h2e: out = 5;
			8'h36: out = 6;
			8'h3d: out = 7;
			8'h3e: out = 8;
			8'h46: out = 9;
			default: valid = 0;
		endcase
	end

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		code <= 8'h45;
		@(negedge clk) wavedrom_start("Decode scancodes");
			@(posedge clk) code <= 8'h45;
			@(posedge clk) code <= 8'h03;
			@(posedge clk) code <= 8'h46;
			@(posedge clk) code <= 8'h16;
			@(posedge clk) code <= 8'd26;
			@(posedge clk) code <= 8'h1e;
			@(posedge clk) code <= 8'h25;
			@(posedge clk) code <= 8'h26;
			@(posedge clk) code <= 8'h2e;
			@(posedge clk) code <= $random;
			@(posedge clk) code <= 8'h36;
			@(posedge clk) code <= $random;
			@(posedge clk) code <= 8'h3d;
			@(posedge clk) code <= 8'h3e;
			@(posedge clk) code <= 8'h45;
			@(posedge clk) code <= 8'h46;
			@(posedge clk) code <= $random;
			@(posedge clk) code <= $random;
			@(posedge clk) code <= $random;
			@(posedge clk) code <= $random;
		wavedrom_stop();

		repeat(1000) @(posedge clk, negedge clk) begin
			code <= $urandom;
		end

		$finish;
	end

endmodule

module tb();

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

		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] code;
	logic [3:0] out_ref;
	logic [3:0] out_dut;
	logic valid_ref;
	logic valid_dut;

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

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.code );
	reference_module good1 (
		.code,
		.out(out_ref),
		.valid(valid_ref) );

	top_module top_module1 (
		.code,
		.out(out_dut),
		.valid(valid_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");
		if (stats1.errors_valid) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "valid", stats1.errors_valid, stats1.errortime_valid);
		else $display("Hint: Output '%s' has no mismatches.", "valid");

		$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, valid_ref } === ( { out_ref, valid_ref } ^ { out_dut, valid_dut } ^ { out_ref, valid_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
		if (valid_ref !== ( valid_ref ^ valid_dut ^ valid_ref ))
		begin if (stats1.errors_valid == 0) stats1.errortime_valid = $time;
			stats1.errors_valid = stats1.errors_valid+1'b1; end

	end
endmodule

detail_description: This top Verilog module is a keyboard module. It takes an 8-bit code as an input and outputs a 4-bit number and a valid bit. The 8-bit input, code, is a scancode generated by the keyboard. The 4-bit output, out, represents a 4-bit number represented by a key. The 1-bit output, valid, indicates whether a key is valid.  The 4-bit output, out, is assigned to 0. The 1-bit output, valid, is assigned to 1. Then, the module uses a case statement to assign the output based on the value of the 8-bit input, code. If the 8-bit input is 8'h45, 8'h16, 8'h1e, 8'h26, 8'h25, 8'h2e, 8'h36, 8'h3d, 8'h3e, or 8'h46, the 4-bit output will be set to 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 respectively. If the 8-bit input does not match any of the cases, the 1-bit output, valid, will be set to 0.


task_id: vectorr

prompt:
module top_module (
	input [7:0] in,
	output [7:0] out
);

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

	assign {out[0],out[1],out[2],out[3],out[4],out[5],out[6],out[7]} = in;

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		in <= 0;
		@(negedge clk) wavedrom_start();
			@(posedge clk) in <= 8'h1;
			@(posedge clk) in <= 8'h2;
			@(posedge clk) in <= 8'h4;
			@(posedge clk) in <= 8'h8;
			@(posedge clk) in <= 8'h80;
			@(posedge clk) in <= 8'hc0;
			@(posedge clk) in <= 8'he0;
			@(posedge clk) in <= 8'hf0;
		@(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 [7:0] 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

detail_description: This top Verilog module is a 8-bit unidirectional data port. It takes an 8-bit input in, and outputs an 8-bit signal out. The output of the module is assigned to out based on the value of in. If in = {a,b,c,d,e,f,g,h}, then out = {h,g,f,e,d,c,b,a}.


prompt:
module top_module (
	input a,
	input b,
	input c,
	input d,
	output reg out
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input a,
	input b,
	input c,
	input d,
	output reg out
);

    always @(*) begin
        case({a,b,c,d})
            4'h0: out = 0;
            4'h1: out = 0;
            4'h3: out = 1;
            4'h2: out = 1;
            4'h4: out = 1'bx;
            4'h5: out = 0;
            4'h7: out = 0;
            4'h6: out = 0;
            4'hc: out = 1;
            4'hd: out = 1'bx;
            4'hf: out = 1;
            4'he: out = 1;
            4'h8: out = 1;
            4'h9: out = 1'bx;
            4'hb: out = 1;
            4'ha: out = 1;
        endcase
    end
endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

	initial begin
		int count; count = 0;
		{a,b,c,d} <= 4'b0;
		wavedrom_start();
		repeat(16) @(posedge clk)
			{a,b,c,d} <= count++;
		@(negedge clk) wavedrom_stop();

		repeat(200) @(posedge clk, negedge clk)
			{d,c,b,a} <= $urandom;

		#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 a;
	logic b;
	logic c;
	logic d;
	logic out_ref;
	logic out_dut;

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

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b,
		.c,
		.d );
	reference_module good1 (
		.a,
		.b,
		.c,
		.d,
		.out(out_ref) );

	top_module top_module1 (
		.a,
		.b,
		.c,
		.d,
		.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

detail_description:
    the functionality of the top Verilog module is a decoder.
    if a,b,c,d == 0, the output is 0;
    if a,b,c,d == 1, the output is 0;
    if a,b,c,d == 3, the output is 1;
    if a,b,c,d == 2, the output is 1;
    if a,b,c,d == 4, the output is 1'bx;
    if a,b,c,d == 5, the output is 0;
    if a,b,c,d == 7, the output is 0;
    if a,b,c,d == 6, the output is 0;
    if a,b,c,d == c, the output is 1;
    if a,b,c,d == d, the output is 1'bx;
    if a,b,c,d == f, the output is 1;
    if a,b,c,d == e, the output is 1;
    if a,b,c,d == 8, the output is 1;
    if a,b,c,d == 9, the output is 1'bx;
    if a,b,c,d == b, the output is 1;
    if a,b,c,d == a, the output is 1;


prompt:
module top_module(
	input clk,
	input shift_ena,
	input count_ena,
	input data,
	output reg [3:0] q);

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

	always @(posedge clk) begin
		if (shift_ena)
			q <= { q[2:0], data };
		else if (count_ena)
			q <= q - 1'b1;
	end

endmodule

module stimulus_gen (
	input clk,
	output reg shift_ena, count_ena, 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;
		shift_ena <= 1;
		count_ena <= 0;
		repeat(5) @(posedge clk);

		data <= 1;
		shift_ena <= 0;
		count_ena <= 0;
		@(posedge clk);
		wavedrom_start("Shift mode");
		@(posedge clk) shift_ena <= 1;
		repeat(2) @(posedge clk) shift_ena <= 0;
		@(posedge clk) shift_ena <= 1;
		repeat(4) @(posedge clk);
		@(posedge clk) data <= 0;
		repeat(4) @(posedge clk);
		wavedrom_stop();

		data <= 1;
		shift_ena <= 1;
		repeat(4) @(posedge clk);
		shift_ena <= 0;
		wavedrom_start("Count mode");
		@(posedge clk) count_ena <= 1;
		repeat(2) @(posedge clk) count_ena <= 0;
		@(posedge clk) count_ena <= 1;
		repeat(4) @(posedge clk);
		@(posedge clk) data <= 0;
		repeat(4) @(posedge clk);
		wavedrom_stop();

		repeat(2000) @(posedge clk, negedge clk) begin
			{shift_ena, count_ena} <= $unsigned($random) % 3;
			data <= $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 shift_ena;
	logic count_ena;
	logic data;
	logic [3:0] q_ref;
	logic [3:0] q_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.shift_ena,
		.count_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

simple_description: This module shifts or counts down a 4-bit register based on the values of the shift_ena and count_ena inputs.

detail_description: This Verilog module is a 4-bit counter with a shift register. It has 5 inputs and 1 output. The inputs are a clock (clk), a shift enable (shift_ena), a count enable (count_ena), and data (data). The output is a 4-bit register (q).  The module is triggered by the clock signal (clk). When the clock signal is high, the module will check the two enable signals (shift_ena and count_ena). If the shift_ena signal is high, the module will shift the data input (data) into the 4-bit register (q). If the count_ena signal is high, the module will decrement the 4-bit register (q). If both enable signals are low, the module will not do anything.