module accumulator(input clk, reset, input [15:0] in, output reg [15:0] out); reg [15:0] sum; wire [15:0] carry; assign carry[0] = 1'b0; genvar i; generate for (i = 1; i < 16; i = i + 1) begin : adder full_adder adder(clk, reset, in[i], sum[i-1], carry[i-1], sum[i], carry[i]); end endgenerate always @(posedge clk) begin if (reset) begin sum <= 16'h0000; out <= 16'h0000; end else begin sum <= sum + in; out <= sum; end end endmodule module full_adder(input clk, reset, input a, b, c_in, output reg s, c_out); always @(posedge clk) begin if (reset) begin s <= 1'b0; c_out <= 1'b0; end else begin s <= a ^ b ^ c_in; c_out <= (a & b) | (a & c_in) | (b & c_in); end end endmodule为以上代码编写测试激励

以下是一个可能的测试激励代码：

`timescale 1ns / 1ps

module accumulator_tb;

// Inputs
reg clk;
reg reset;
reg [15:0] in;

// Outputs
wire [15:0] out;

// Instantiate the Unit Under Test (UUT)
accumulator uut (
    .clk(clk),
    .reset(reset),
    .in(in),
    .out(out)
);

initial begin
    // Initialize inputs
    clk = 0;
    reset = 1;
    in = 16'h0000;

    // Wait for 10 clock cycles
    #10;

    // Deassert reset
    reset = 0;

    // Test case 1: Add 1 to accumulator
    in = 16'h0001;
    #10;
    if (out !== 16'h0001) $display("Test case 1 failed: Expected out = 16'h0001, Actual out = %h", out);

    // Test case 2: Add 2 to accumulator
    in = 16'h0002;
    #10;
    if (out !== 16'h0003) $display("Test case 2 failed: Expected out = 16'h0003, Actual out = %h", out);

    // Test case 3: Add -1 to accumulator
    in = 16'hFFFF;
    #10;
    if (out !== 16'h0002) $display("Test case 3 failed: Expected out = 16'h0002, Actual out = %h", out);

    // Test case 4: Add 0 to accumulator
    in = 16'h0000;
    #10;
    if (out !== 16'h0002) $display("Test case 4 failed: Expected out = 16'h0002, Actual out = %h", out);

    $display("Testing completed successfully!");
    $finish;
end

// Toggle clock every 5 ns
always #5 clk <= ~clk;

endmodule

这个测试激励会对累加器进行四个测试，分别是：

1. 将1加入累加器，期望输出为1
2. 将2加入累加器，期望输出为3
3. 将-1加入累加器，期望输出为2
4. 将0加入累加器，期望输出为2

测试激励会在每个测试之间等待10个时钟周期，同时会在仿真结束时输出测试结果。注意，测试中并没有对溢出情况进行测试。