prompt:
module top_module (
	input [99:0] in,
	output out_and,
	output out_or,
	output out_xor
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [99:0] in,
	output out_and,
	output out_or,
	output out_xor
);

	assign out_and = ∈
	assign out_or = |in;
	assign out_xor = ^in;

endmodule

module stimulus_gen (
	input clk,
	input tb_match,
	output logic [99:0] 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
		reg [3:0] count; count = 0;
		in <= 100'h0;
		// AND gate uses huge numbers and creates a sparse waveform.
		@(negedge clk) wavedrom_start("Test AND gate");
			@(posedge clk,negedge clk) in <= 100'h0;		// Test OR gate
			@(posedge clk,negedge clk); in <= ~100'h0;		// Test AND gate
			@(posedge clk,negedge clk); in <= 100'h3ffff;
			@(posedge clk,negedge clk); in <= ~100'h3ffff;
			@(posedge clk,negedge clk); in <= 100'h80;
			@(posedge clk,negedge clk); in <= ~100'h80;
		wavedrom_stop();

		@(negedge clk) wavedrom_start("Test OR and XOR gates");
			@(posedge clk) in <= 100'h0;		// Test OR gate
			@(posedge clk); in <= 100'h7;		// Test AND gate
			repeat(10) @(posedge clk, negedge clk) begin
				in <= count;
				count <= count + 1;
			end
			@(posedge clk) in <= 100'h0;
		@(negedge clk) wavedrom_stop();

		in <= $random;
		repeat(100) begin
			@(negedge clk) in <= $random;
			@(posedge clk) in <= $random;
		end
		for (int i=0;i<100;i++) begin
			@(negedge clk) in <= 100'h1<<i;
			@(posedge clk) in <= ~(100'h1<<i);
		end
		@(posedge clk) in <= 100'h0;		// Test OR gate
		@(posedge clk); in <= ~100'h0;		// Test AND gate
		@(posedge clk);
		#1 $finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_out_and;
		int errortime_out_and;
		int errors_out_or;
		int errortime_out_or;
		int errors_out_xor;
		int errortime_out_xor;

		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 [99:0] in;
	logic out_and_ref;
	logic out_and_dut;
	logic out_or_ref;
	logic out_or_dut;
	logic out_xor_ref;
	logic out_xor_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,in,out_and_ref,out_and_dut,out_or_ref,out_or_dut,out_xor_ref,out_xor_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.in );
	reference_module good1 (
		.in,
		.out_and(out_and_ref),
		.out_or(out_or_ref),
		.out_xor(out_xor_ref) );

	top_module top_module1 (
		.in,
		.out_and(out_and_dut),
		.out_or(out_or_dut),
		.out_xor(out_xor_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_and) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out_and", stats1.errors_out_and, stats1.errortime_out_and);
		else $display("Hint: Output '%s' has no mismatches.", "out_and");
		if (stats1.errors_out_or) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out_or", stats1.errors_out_or, stats1.errortime_out_or);
		else $display("Hint: Output '%s' has no mismatches.", "out_or");
		if (stats1.errors_out_xor) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "out_xor", stats1.errors_out_xor, stats1.errortime_out_xor);
		else $display("Hint: Output '%s' has no mismatches.", "out_xor");

		$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_and_ref, out_or_ref, out_xor_ref } === ( { out_and_ref, out_or_ref, out_xor_ref } ^ { out_and_dut, out_or_dut, out_xor_dut } ^ { out_and_ref, out_or_ref, out_xor_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_and_ref !== ( out_and_ref ^ out_and_dut ^ out_and_ref ))
		begin if (stats1.errors_out_and == 0) stats1.errortime_out_and = $time;
			stats1.errors_out_and = stats1.errors_out_and+1'b1; end
		if (out_or_ref !== ( out_or_ref ^ out_or_dut ^ out_or_ref ))
		begin if (stats1.errors_out_or == 0) stats1.errortime_out_or = $time;
			stats1.errors_out_or = stats1.errors_out_or+1'b1; end
		if (out_xor_ref !== ( out_xor_ref ^ out_xor_dut ^ out_xor_ref ))
		begin if (stats1.errors_out_xor == 0) stats1.errortime_out_xor = $time;
			stats1.errors_out_xor = stats1.errors_out_xor+1'b1; end

	end
endmodule

simple_description: This module takes a 100-bit input and outputs the bitwise AND, OR, and XOR of the input.

detail_description: This module is used to perform logical operations on a 100-bit input vector. The module has four ports: an input port, in, and three output ports, out_and, out_or, and out_xor. The input port, in, is a 100-bit vector. The output ports, out_and, out_or, and out_xor, are all single-bit outputs.  The module performs the logical operations of AND, OR, and XOR on the input vector. The AND operation is performed by taking the logical AND of all the bits in the input vector, and assigning the result to the out_and output port. The OR operation is performed by taking the logical OR of all the bits in the input vector, and assigning the result to the out_or output port. The XOR operation is performed by taking the logical XOR of all the bits in the input vector, and assigning the result to the out_xor output port.


task_id: hadd

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

canonical_solution:
	assign {cout, sum} = a+b;

endmodule

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

	assign {cout, sum} = a+b;

endmodule

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

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

	initial begin
		repeat(100) @(negedge clk);
		$finish;
	end

endmodule
module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_sum;
		int errortime_sum;
		int errors_cout;
		int errortime_cout;

		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 sum_ref;
	logic sum_dut;
	logic cout_ref;
	logic cout_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,sum_ref,sum_dut,cout_ref,cout_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b );
	reference_module good1 (
		.a,
		.b,
		.sum(sum_ref),
		.cout(cout_ref) );

	top_module top_module1 (
		.a,
		.b,
		.sum(sum_dut),
		.cout(cout_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_sum) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "sum", stats1.errors_sum, stats1.errortime_sum);
		else $display("Hint: Output '%s' has no mismatches.", "sum");
		if (stats1.errors_cout) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "cout", stats1.errors_cout, stats1.errortime_cout);
		else $display("Hint: Output '%s' has no mismatches.", "cout");

		$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 = ( { sum_ref, cout_ref } === ( { sum_ref, cout_ref } ^ { sum_dut, cout_dut } ^ { sum_ref, cout_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 (sum_ref !== ( sum_ref ^ sum_dut ^ sum_ref ))
		begin if (stats1.errors_sum == 0) stats1.errortime_sum = $time;
			stats1.errors_sum = stats1.errors_sum+1'b1; end
		if (cout_ref !== ( cout_ref ^ cout_dut ^ cout_ref ))
		begin if (stats1.errors_cout == 0) stats1.errortime_cout = $time;
			stats1.errors_cout = stats1.errors_cout+1'b1; end

	end
endmodule

simple_description: This module takes two inputs, a and b, and produces two outputs, sum and cout, which are the sum and carryout of the addition of a and b.

detail_description: This top Verilog module is a simple adder module that takes two inputs, a and b, and produces two outputs, sum and cout. The sum output is the result of adding the two inputs together, while the cout output is the carry out of the addition.   The module begins by declaring the four ports, two inputs (a and b) and two outputs (sum and cout). The assign statement then assigns the two outputs to the result of the addition of the two inputs. The addition is done using the + operator, which adds the two inputs together and produces the sum output and the carry out, which is stored in the cout output.   This module is a simple, yet effective way to add two numbers together and produce the sum and carry out outputs. It is a useful module for any application that requires addition of two numbers.


prompt:
module top_module (
	input cpu_overheated,
	output reg shut_off_computer,
	input arrived,
	input gas_tank_empty,
	output reg keep_driving
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input cpu_overheated,
	output reg shut_off_computer,
	input arrived,
	input gas_tank_empty,
	output reg keep_driving
);

	always @(*) begin
		if (cpu_overheated)
			shut_off_computer = 1;
		else
			shut_off_computer = 0;
	end

	always @(*) begin
		if (~arrived)
			keep_driving = !gas_tank_empty;
		else
			keep_driving = 1'b0;
	end

endmodule

module stimulus_gen (
	input clk,
	output logic cpu_overheated, arrived, gas_tank_empty,
	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

	logic [2:0] s = 3'b010;
	assign {cpu_overheated, arrived, gas_tank_empty} = s;

	initial begin
		@(negedge clk) wavedrom_start("");
		@(posedge clk) s <= 3'b010;
		@(posedge clk) s <= 3'b100;
		@(posedge clk) s <= 3'b100;
		@(posedge clk) s <= 3'b001;
		@(posedge clk) s <= 3'b000;
		@(posedge clk) s <= 3'b100;
		@(posedge clk) s <= 3'b110;
		@(posedge clk) s <= 3'b111;
		@(posedge clk) s <= 3'b111;
		@(posedge clk) s <= 3'b111;
		wavedrom_stop();
		repeat(100) @(posedge clk, negedge clk)
			s <= $urandom;
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_shut_off_computer;
		int errortime_shut_off_computer;
		int errors_keep_driving;
		int errortime_keep_driving;

		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 cpu_overheated;
	logic arrived;
	logic gas_tank_empty;
	logic shut_off_computer_ref;
	logic shut_off_computer_dut;
	logic keep_driving_ref;
	logic keep_driving_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,cpu_overheated,arrived,gas_tank_empty,shut_off_computer_ref,shut_off_computer_dut,keep_driving_ref,keep_driving_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.cpu_overheated,
		.arrived,
		.gas_tank_empty );
	reference_module good1 (
		.cpu_overheated,
		.arrived,
		.gas_tank_empty,
		.shut_off_computer(shut_off_computer_ref),
		.keep_driving(keep_driving_ref) );

	top_module top_module1 (
		.cpu_overheated,
		.arrived,
		.gas_tank_empty,
		.shut_off_computer(shut_off_computer_dut),
		.keep_driving(keep_driving_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_shut_off_computer) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "shut_off_computer", stats1.errors_shut_off_computer, stats1.errortime_shut_off_computer);
		else $display("Hint: Output '%s' has no mismatches.", "shut_off_computer");
		if (stats1.errors_keep_driving) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "keep_driving", stats1.errors_keep_driving, stats1.errortime_keep_driving);
		else $display("Hint: Output '%s' has no mismatches.", "keep_driving");

		$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 = ( { shut_off_computer_ref, keep_driving_ref } === ( { shut_off_computer_ref, keep_driving_ref } ^ { shut_off_computer_dut, keep_driving_dut } ^ { shut_off_computer_ref, keep_driving_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 (shut_off_computer_ref !== ( shut_off_computer_ref ^ shut_off_computer_dut ^ shut_off_computer_ref ))
		begin if (stats1.errors_shut_off_computer == 0) stats1.errortime_shut_off_computer = $time;
			stats1.errors_shut_off_computer = stats1.errors_shut_off_computer+1'b1; end
		if (keep_driving_ref !== ( keep_driving_ref ^ keep_driving_dut ^ keep_driving_ref ))
		begin if (stats1.errors_keep_driving == 0) stats1.errortime_keep_driving = $time;
			stats1.errors_keep_driving = stats1.errors_keep_driving+1'b1; end

	end
endmodule

simple_description: This module is responsible for controlling the shut-off of the computer and the driving of the car based on the inputs of cpu_overheated, arrived, and gas_tank_empty.

detail_description: This top Verilog module is used to control the behavior of a computer and a car. The module has four inputs and two outputs. The first input is a signal called "cpu_overheated" which is used to indicate whether the computer is overheating. The second input is a signal called "arrived" which is used to indicate whether the car has arrived at its destination. The third input is a signal called "gas_tank_empty" which is used to indicate whether the car's gas tank is empty. The fourth input is a signal called "shut_off_computer" which is used to shut off the computer. The two outputs are signals called "keep_driving" and "shut_off_computer".   The module contains two always blocks. The first always block is used to control the "shut_off_computer" output. If the "cpu_overheated" input is high, the "shut_off_computer" output will be set to 1, otherwise it will be set to 0. The second always block is used to control the "keep_driving" output. If the "arrived" input is low, the "keep_driving" output will be set to the inverse of the "gas_tank_empty" input, otherwise it will be set to 0.


prompt:
module top_module (
	input clk,
	input j,
	input k,
	input reset,
	output out
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input j,
	input k,
	input reset,
	output out
);
	parameter A=0, B=1;
	reg state;
	reg next;

    always_comb begin
		case (state)
			A: next = j ? B : A;
			B: next = k ? A : B;
		endcase
    end

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

	assign out = (state==B);

endmodule

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

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

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

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

	endtask

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

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

	task wavedrom_stop;
		#1;
	endtask

	reg [0:11][1:0] d = 24'b000101010010101111111111;

	initial begin
		reset <= 1;
		j <= 0;
		k <= 0;
		@(posedge clk);
		reset <= 0;
		j <= 1;
		@(posedge clk);
		j <= 0;
		wavedrom_start("Reset and transitions");
		reset_test();
		for (int i=0;i<12;i++)
			@(posedge clk) {k, j} <= d[i];
		wavedrom_stop();
		repeat(200) @(posedge clk, negedge clk) begin
			{j,k} <= $random;
			reset <= !($random & 7);
		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 j;
	logic k;
	logic reset;
	logic out_ref;
	logic out_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.j,
		.k,
		.reset,
		.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 implements a two-state finite state machine with two inputs (j and k) and one output (out) that is set to 1 when the state is B.

detail_description: This Verilog module is a two-state state machine with two inputs and one output. The two inputs are j and k, and the output is out. The two states are A and B, and the module is initialized to state A.   The module has a clock input, clk, and a reset input. When the reset input is high, the state is set to A. When the reset input is low, the state is determined by the two inputs j and k.   When the state is A, the next state is determined by the input j. If j is high, the next state is B. If j is low, the next state remains A. When the state is B, the next state is determined by the input k. If k is high, the next state is A. If k is low, the next state remains B.   The output out is high when the state is B, and low when the state is A.


prompt:
module top_module (
	input [4:0] a,
	input [4:0] b,
	input [4:0] c,
	input [4:0] d,
	input [4:0] e,
	input [4:0] f,
	output [7:0] w,
	output [7:0] x,
	output [7:0] y,
	output [7:0] z
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input [4:0] a,
	input [4:0] b,
	input [4:0] c,
	input [4:0] d,
	input [4:0] e,
	input [4:0] f,
	output [7:0] w,
	output [7:0] x,
	output [7:0] y,
	output [7:0] z
);

	assign { w,x,y,z} = {a,b,c,d,e,f,2'b11};

endmodule

module stimulus_gen (
	input clk,
	output logic [4:0] a,b,c,d,e,f,
	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
		wavedrom_start("");
		@(posedge clk) {a,b,c,d,e,f} <= '0;
		@(posedge clk) {a,b,c,d,e,f} <= 1;
		@(posedge clk) {a,b,c,d,e,f} <= 2;
		@(posedge clk) {a,b,c,d,e,f} <= 4;
		@(posedge clk) {a,b,c,d,e,f} <= 8;
		@(posedge clk) {a,b,c,d,e,f} <= 'h10;
		@(posedge clk) {a,b,c,d,e,f} <= 'h20;
		@(posedge clk) {a,b,c,d,e,f} <= 'h40;
		@(posedge clk) {a,b,c,d,e,f} <= 'h80;
		@(posedge clk) {a,b,c,d,e,f} <= 'h100;
		@(posedge clk) {a,b,c,d,e,f} <= 'h200;
		@(posedge clk) {a,b,c,d,e,f} <= 'h400;
		@(posedge clk) {a,b,c,d,e,f} <= {5'h1f, 5'h0, 5'h1f, 5'h0, 5'h1f, 5'h0};
		@(negedge clk);
		wavedrom_stop();
		repeat(100) @(posedge clk, negedge clk)
			{a,b,c,d,e,f} <= $random;
		$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 [4:0] a;
	logic [4:0] b;
	logic [4:0] c;
	logic [4:0] d;
	logic [4:0] e;
	logic [4:0] f;
	logic [7:0] w_ref;
	logic [7:0] w_dut;
	logic [7:0] x_ref;
	logic [7:0] x_dut;
	logic [7:0] y_ref;
	logic [7:0] y_dut;
	logic [7:0] z_ref;
	logic [7:0] z_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,c,d,e,f,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,
		.d,
		.e,
		.f );
	reference_module good1 (
		.a,
		.b,
		.c,
		.d,
		.e,
		.f,
		.w(w_ref),
		.x(x_ref),
		.y(y_ref),
		.z(z_ref) );

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

detail_description:
The top module contains 6 ports that are fed into a concatenation which outputs 4 ports.
The first input "a" is fed into the first port in the concatenation, the second input "b" is fed into the second port of the concatenation, the third input "c" is fed into the third port of the concatenation, the fourth input "d" is fed into the fourth port of the concatenation, the fifth input "e" is fed into the fifth port of the concatenation, the sixth input "f" is fed into the sixth port of the concatenation. The last bit of the concatenation is 2'b11. This value is fed in to the last port of the concatenation.


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

canonical_solution:
	assign q = ~a^b^c^d;

endmodule

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

	assign q = ~a^b^c^d;

endmodule

module stimulus_gen (
	input clk,
	output logic 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
		{a,b,c,d} <= 0;
		@(negedge clk) wavedrom_start("Unknown circuit");
			@(posedge clk) {a,b,c,d} <= 0;
			repeat(18) @(posedge clk, negedge clk) {a,b,c,d} <= {a,b,c,d} + 1;
		wavedrom_stop();

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

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,c,d,q_ref,q_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,
		.q(q_ref) );

	top_module top_module1 (
		.a,
		.b,
		.c,
		.d,
		.q(q_dut) );

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

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

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

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

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

	end
endmodule

simple_description: This module assigns the output q to the bitwise XOR of the inputs a, b, c, and d.

detail_description: This Verilog module implements a logic function that takes four inputs (a, b, c, and d) and produces one output (q). It performs a bitwise XOR operation on the inputs, and then inverts the result. This means that the output will be high when an odd number of inputs are high, and low when an even number of inputs are high.


task_id: andgate

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

canonical_solution:
	assign out = a & b;

endmodule

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

	assign out = a & b;

endmodule

module stimulus_gen (
	input clk,
	output reg 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
		int count; count = 0;
		{a,b} <= 1'b0;
		wavedrom_start("AND gate");
		repeat(10) @(posedge clk)
			{a,b} <= count++;
		wavedrom_stop();

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

		#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 out_ref;
	logic out_dut;

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

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

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

	top_module top_module1 (
		.a,
		.b,
		.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 assigns the output 'out' to the logical AND of inputs 'a' and 'b'.

detail_description: This top Verilog module is a simple logic gate that performs a logical AND operation on two input signals, a and b, and outputs the result on the out signal. The module has three ports, two inputs (a and b) and one output (out). The two inputs are connected to the logical AND gate, which produces the output signal out. The output signal out is the result of the logical AND operation between the two input signals a and b. The output signal out will be high (1) if both input signals a and b are high (1) and low (0) if either of the input signals a or b is low (0).


prompt:
module top_module (
	input clk,
	input in,
	input reset,
	output out
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input clk,
	input in,
	input reset,
	output out
);
	parameter A=0, B=1;
	reg state;
	reg next;

    always_comb begin
		case (state)
			A: next = in ? A : B;
			B: next = in ? B : A;
		endcase
    end

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

	assign out = (state==B);

endmodule

module stimulus_gen (
	input clk,
	output logic in,
	output logic 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;
		in <= 0;
		@(posedge clk);
		@(posedge clk) reset <= 0; in <= 0;
		@(posedge clk) in <= 1;
		wavedrom_start();
			reset_test(0);
			@(posedge clk) in <= 0;
			@(posedge clk) in <= 0;
			@(posedge clk) in <= 0;
			@(posedge clk) in <= 1;
			@(posedge clk) in <= 1;
		@(negedge clk);
		wavedrom_stop();
		repeat(200) @(posedge clk, negedge clk) begin
			in <= $random;
			reset <= !($random & 7);
		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 in;
	logic reset;
	logic out_ref;
	logic out_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.in,
		.reset,
		.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: The top Verilog module implements a state machine that toggles between two states based on the input signal, and outputs a signal when the state is B.

detail_description: The top Verilog module is a simple state machine with two states, A and B. It has four inputs: clk, in, reset, and out, and one output, out. The clk input is used to trigger the state machine, the in input is used to determine which state to transition to, the reset input is used to reset the state machine to the initial state, and the out output is used to indicate the current state.  The module is implemented using a parameterized register, state, and a combinational logic block. The parameterized register, state, is used to store the current state of the state machine. The combinational logic block is used to determine the next state of the state machine based on the current state and the in input. If the current state is A, the next state will be A if the in input is high, and B if the in input is low. If the current state is B, the next state will be B if the in input is high, and A if the in input is low.  The module also contains an always block triggered on the rising edge of the clk input. This block is used to update the state register with the next state determined by the combinational logic block. If the reset input is high, the state register is reset to the initial state, B. Otherwise, the state register is updated with the next state determined by the combinational logic block.  Finally, the out output is assigned the value of the state register. If the state register is B, the out output will be high, otherwise it will be low.


task_id: fadd

prompt:
module top_module (
	input a,
	input b,
	input cin,
	output cout,
	output sum
);

canonical_solution:
	assign {cout, sum} = a+b+cin;

endmodule

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

	assign {cout, sum} = a+b+cin;

endmodule

module stimulus_gen (
	input clk,
	output logic a,b,cin,
	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
		wavedrom_start();
			@(posedge clk) {a,b,cin} <= 3'b000;
			@(posedge clk) {a,b,cin} <= 3'b010;
			@(posedge clk) {a,b,cin} <= 3'b100;
			@(posedge clk) {a,b,cin} <= 3'b110;
			@(posedge clk) {a,b,cin} <= 3'b000;
			@(posedge clk) {a,b,cin} <= 3'b001;
			@(posedge clk) {a,b,cin} <= 3'b011;
		@(negedge clk) wavedrom_stop();

		repeat(200) @(posedge clk, negedge clk)
			{a,b,cin} <= $random;
		$finish;
	end

endmodule

module tb();

	typedef struct packed {
		int errors;
		int errortime;
		int errors_cout;
		int errortime_cout;
		int errors_sum;
		int errortime_sum;

		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 cin;
	logic cout_ref;
	logic cout_dut;
	logic sum_ref;
	logic sum_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,a,b,cin,cout_ref,cout_dut,sum_ref,sum_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.a,
		.b,
		.cin );
	reference_module good1 (
		.a,
		.b,
		.cin,
		.cout(cout_ref),
		.sum(sum_ref) );

	top_module top_module1 (
		.a,
		.b,
		.cin,
		.cout(cout_dut),
		.sum(sum_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_cout) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "cout", stats1.errors_cout, stats1.errortime_cout);
		else $display("Hint: Output '%s' has no mismatches.", "cout");
		if (stats1.errors_sum) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "sum", stats1.errors_sum, stats1.errortime_sum);
		else $display("Hint: Output '%s' has no mismatches.", "sum");

		$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 = ( { cout_ref, sum_ref } === ( { cout_ref, sum_ref } ^ { cout_dut, sum_dut } ^ { cout_ref, sum_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 (cout_ref !== ( cout_ref ^ cout_dut ^ cout_ref ))
		begin if (stats1.errors_cout == 0) stats1.errortime_cout = $time;
			stats1.errors_cout = stats1.errors_cout+1'b1; end
		if (sum_ref !== ( sum_ref ^ sum_dut ^ sum_ref ))
		begin if (stats1.errors_sum == 0) stats1.errortime_sum = $time;
			stats1.errors_sum = stats1.errors_sum+1'b1; end

	end
endmodule

simple_description: This module takes in three inputs (a, b, and cin) and outputs the sum and carry out of the addition.

detail_description: This Verilog module is a simple adder that takes three inputs (a, b, and cin) and outputs two values (cout and sum). The inputs a and b are the two numbers to be added, while cin is the carry-in bit. The output cout is the carry-out bit, and sum is the result of the addition of a and b plus the carry-in bit.   The module uses an assign statement to calculate the outputs. The assign statement adds the inputs a and b, plus the carry-in bit, and assigns the result to the outputs cout and sum. The carry-out bit is calculated by determining if the sum of the inputs is greater than or equal to 2. If it is, then the carry-out bit is set to 1, otherwise it is set to 0. The sum output is the result of the addition of a, b, and cin, modulo 2.


prompt:
module top_module (
	input in1,
	input in2,
	input in3,
	output logic out
);

test:
`timescale 1 ps/1 ps
`define OK 12
`define INCORRECT 13
module reference_module (
	input in1,
	input in2,
	input in3,
	output logic out
);

	assign out = (~(in1 ^ in2)) ^ in3;
endmodule

module stimulus_gen (
	input clk,
	output logic in1, in2, in3
);

	initial begin
		repeat(100) @(posedge clk, negedge clk) begin
			{in1, in2, in3} <= $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 in3;
	logic out_ref;
	logic out_dut;

	initial begin
		$dumpfile("wave.vcd");
		$dumpvars(1, stim1.clk, tb_mismatch ,in1,in2,in3,out_ref,out_dut );
	end

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

	stimulus_gen stim1 (
		.clk,
		.* ,
		.in1,
		.in2,
		.in3 );
	reference_module good1 (
		.in1,
		.in2,
		.in3,
		.out(out_ref) );

	top_module top_module1 (
		.in1,
		.in2,
		.in3,
		.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 assigns the output to the XOR of the inverse of the XOR of the inputs in1 and in2 and the input in3.

detail_description: This Verilog module takes three inputs, in1, in2, and in3, and produces a single output, out. The output is calculated by performing a bitwise XOR operation on in1 and in2, and then performing a bitwise NOT operation on the result, followed by another bitwise XOR operation with in3. In other words, the output is equal to (NOT (in1 XOR in2)) XOR in3.


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

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

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

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

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

		$finish;
	end

endmodule

module tb();

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

		int clocks;
	} stats;

	stats stats1;

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

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

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

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

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

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

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

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

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

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

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

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

	end
endmodule

simple_description: This module assigns the inputs c and d to the outputs mux_in[0], mux_in[2], and mux_in[3], and assigns 0 to mux_in[1].

detail_description: This top Verilog module is a 4-to-1 multiplexer. It takes two inputs, c and d, and outputs a 4-bit signal mux_in. The output of the multiplexer is determined by the values of the two inputs. The output of the multiplexer is assigned to the 4-bit signal mux_in. The first bit of mux_in is assigned to the logical OR of the two inputs, c and d. The second bit of mux_in is assigned to 0. The third bit of mux_in is assigned to the logical NOT of the input d. The fourth bit of mux_in is assigned to the logical AND of the two inputs, c and d.


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

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

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

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

endmodule

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

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

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

	task wavedrom_stop;
		#1;
	endtask

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

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

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

	endtask

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

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

		$finish;
	end

endmodule

module tb();

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

		int clocks;
	} stats;

	stats stats1;

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

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

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

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

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

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

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

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

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

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

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

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

	end
endmodule

simple_description: This module implements a state machine which outputs z depending on the current state and the input x.

detail_description: This Verilog module is a state machine that has two states, A and B, and is used to detect a rising edge on the input x. The module has four inputs and one output. The inputs are clk, areset, and x, while the output is z. The clk input is the clock signal used to synchronize the state machine, the areset input is the asynchronous reset signal, and the x input is the signal that is being monitored for a rising edge. The output z is a signal that is set to 1 when a rising edge is detected on the x input.  The module has a parameter, A and B, which are used to define the two states of the state machine. The state of the state machine is stored in a register called state. The state machine is clocked by the posedge of the clk input. When the areset input is asserted, the state is set to A. When the areset input is not asserted, the state is determined by the case statement. If the state is A, then the state will be set to B if the x input is 1, otherwise the state will remain A. If the state is B, then the state will remain B.  The output z is set to 1 when the state is A and the x input is 1, or when the state is B and the x input is 0. Otherwise, the output z is 0.


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

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

	reg c;
	always @(posedge clk)
		c <= a&b | a&c | b&c;

	assign q = a^b^c;
	assign state = c;

endmodule

module stimulus_gen (
	input clk,
	output logic a,
	output logic 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 <= 1;
		@(negedge clk) {a,b} <= 0;
		@(negedge clk) wavedrom_start("Unknown circuit");
			repeat(3) @(posedge clk);
			{a,b} <= 1;
			@(posedge clk) {a,b} <= 2;
			@(posedge clk) {a,b} <= 3;
			@(posedge clk) {a,b} <= 0;
			@(posedge clk) {a,b} <= 3;
			@(posedge clk) {a,b} <= 3;
			@(posedge clk) {a,b} <= 3;
			@(posedge clk) {a,b} <= 2;
			@(posedge clk) {a,b} <= 1;
			@(posedge clk) {a,b} <= 0;
			@(posedge clk) {a,b} <= 0;
			@(posedge clk) {a,b} <= 0;
			@(negedge 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 errors_state;
		int errortime_state;

		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;
	logic state_ref;
	logic state_dut;

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

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

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

	top_module top_module1 (
		.clk,
		.a,
		.b,
		.q(q_dut),
		.state(state_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");
		if (stats1.errors_state) $display("Hint: Output '%s' has %0d mismatches. First mismatch occurred at time %0d.", "state", stats1.errors_state, stats1.errortime_state);
		else $display("Hint: Output '%s' has no mismatches.", "state");

		$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, state_ref } === ( { q_ref, state_ref } ^ { q_dut, state_dut } ^ { q_ref, state_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
		if (state_ref !== ( state_ref ^ state_dut ^ state_ref ))
		begin if (stats1.errors_state == 0) stats1.errortime_state = $time;
			stats1.errors_state = stats1.errors_state+1'b1; end

	end
endmodule

simple_description: This module implements a 3-input XOR gate with an additional output for the internal carry state.

detail_description: This module is a sequential circuit with two outputs, q and state. The inputs are clock, a, and b. The clock is used to synchronize the circuit, and the inputs a and b are used to control the circuit's behavior.  The circuit is composed of two main components: a register and an assignment. The register is used to store the value of c, which is calculated from the inputs a and b. The register is clocked by the input clock signal, so that the value of c is updated on each rising edge of the clock. The value of c is calculated as the logical OR of the logical AND of a and b, the logical AND of a and c, and the logical AND of b and c.  The assignment is used to calculate the outputs q and state. The output q is calculated as the logical XOR of a, b, and c. The output state is simply the value of c.


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;
			4'h1: f = 1;
			4'h2: f = 0;
			4'h3: f = 0;
			4'h4: f = 1;
			4'h5: f = 1;
			4'h6: f = 1;
			4'h7: f = 0;
			4'h8: f = 0;
			4'h9: f = 0;
			4'ha: f = 0;
			4'hb: f = 0;
			4'hc: f = 1;
			4'hd: f = 0;
			4'he: f = 1;
			4'hf: f = 1;
		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: This top Verilog module is a 16-state combinational logic block. It takes an input x and outputs a signal f. The input x is a 5-bit signal. The output f is a 1-bit signal. The module is implemented using a case statement. The output of the module is determined by the value of the input x. If x is 0x0, the output will be 1. If x is 0x1, the output will be 1. If x is 0x2, the output will be 0. If x is 0x3, the output will be 0. If x is 0x4, the output will be 1. If x is 0x5, the output will be 1. If x is 0x6, the output will be 1. If x is 0x7, the output will be 0. If x is 0x8, the output will be 0. If x is 0x9, the output will be 0. If x is 0xa, the output will be 0. If x is 0xb, the output will be 0. If x is 0xc, the output will be 1. If x is 0xd, the output will be 0. If x is 0xe, the output will be 1. If x is 0xf, the output will be 1.