请给出用verilog语言实现以下功能的代码：由按键KEY0、KEY1控制计数器的值并在数码管上显示，每按下抬起一次KEY0计数加1，每按下抬起一次KEY1计数减1，计数加到100时归零，按照十进制在数码管的两位上显示,按下复位按钮后计数归零，其中两数码管为共阴极，并给出响应的检测其功能的testbentch测试文件代码

以下是用verilog语言实现以上功能的代码：

module counter(
    input CLK,         //时钟信号
    input RST,         //复位信号
    input KEY0,        //按键0
    input KEY1,        //按键1
    output reg [6:0] SEG_A,    //数码管A
    output reg [6:0] SEG_B     //数码管B
);

reg [6:0] count;       //定义计数器

always @(posedge CLK) begin
    if (RST) begin       //复位信号为高，计数器清零
        count <= 0;
        SEG_A <= 7'b111_1111;    //数码管显示空
        SEG_B <= 7'b111_1111;
    end
    else if (KEY0) begin       //按键0为高，计数器加1
        count <= count + 1;
    end
    else if (KEY1) begin       //按键1为高，计数器减1
        count <= count - 1;
    end
    if (count >= 100) begin       //计数器加到100，归零
        count <= 0;
    end
end

assign SEG_A = {7'b000_0001,  //数码管A的数字编码
                7'b100_1111, 
                7'b001_0010, 
                7'b000_0110, 
                7'b100_1100, 
                7'b010_0100, 
                7'b010_0000, 
                7'b000_1111, 
                7'b000_0000, 
                7'b000_0100};
assign SEG_B = {7'b000_0001,  //数码管B的数字编码
                7'b100_1111, 
                7'b001_0010, 
                7'b000_0110, 
                7'b100_1100, 
                7'b010_0100, 
                7'b010_0000, 
                7'b000_1111, 
                7'b000_0000, 
                7'b000_0100};

always @(*) begin       //根据计数器的值显示在数码管上
    if (count < 10) begin
        SEG_A = SEG_A[count];
        SEG_B = SEG_B[0];
    end
    else begin
        SEG_A = SEG_A[count % 10];
        SEG_B = SEG_B[count / 10];
    end
end

endmodule

以下是响应的testbench测试文件代码：

`timescale 1ns / 1ns

module counter_tb;

reg CLK;
reg RST;
reg KEY0;
reg KEY1;
wire [6:0] SEG_A;
wire [6:0] SEG_B;

counter uut(
    .CLK(CLK),
    .RST(RST),
    .KEY0(KEY0),
    .KEY1(KEY1),
    .SEG_A(SEG_A),
    .SEG_B(SEG_B)
);

initial begin
    CLK = 0;
    forever #5 CLK = ~CLK;
end

initial begin
    RST = 1;
    #10 RST = 0;
end

initial begin
    KEY0 = 0;
    KEY1 = 0;

    //按键0加1
    #10 KEY0 = 1;
    #10 KEY0 = 0;
    #10 KEY0 = 1;
    #10 KEY0 = 0;

    //按键1减1
    #10 KEY1 = 1;
    #10 KEY1 = 0;
    #10 KEY1 = 1;
    #10 KEY1 = 0;

    //计数器加到100
    #200 {KEY0 = 1; KEY0 = 0;} repeat(100);

    //复位计数器
    #10 RST = 1;
    #10 RST = 0;

    //按键1减1
    #10 KEY1 = 1;
    #10 KEY1 = 0;
    #10 KEY1 = 1;
    #10 KEY1 = 0;

    //按键0加1
    #10 KEY0 = 1;
    #10 KEY0 = 0;
    #10 KEY0 = 1;
    #10 KEY0 = 0;

    //计数器加到100
    #200 {KEY0 = 1; KEY0 = 0;} repeat(100);

    //复位计数器
    #10 RST = 1;
    #10 RST = 0;

    //按键0加1
    #10 KEY0 = 1;
    #10 KEY0 = 0;
    #10 KEY0 = 1;
    #10 KEY0 = 0;

    //按键1减1
    #10 KEY1 = 1;
    #10 KEY1 = 0;
    #10 KEY1 = 1;
    #10 KEY1 = 0;

    //计数器加到100
    #200 {KEY0 = 1; KEY0 = 0;} repeat(100);

    //复位计数器
    #10 RST = 1;
    #10 RST = 0;

    //按键1减1
    #10 KEY1 = 1;
    #10 KEY1 = 0;
    #10 KEY1 = 1;
    #10 KEY1 = 0;

    //按键0加1
    #10 KEY0 = 1;
    #10 KEY0 = 0;
    #10 KEY0 = 1;
    #10 KEY0 = 0;

    //计数器加到100
    #200 {KEY0 = 1; KEY0 = 0;} repeat(100);

    $finish;    //结束仿真
end

endmodule