写一个timer的system verlog的测试代码

下面是一个简单的Timer的System Verilog测试代码示例：

module test_timer();

  logic clk;
  logic rst;
  logic start;
  logic [31:0] time;

  Timer dut(clk, rst, start, time);

  initial begin
    clk = 0;
    forever #10 clk = ~clk;
  end

  initial begin
    rst = 1;
    #20 rst = 0;
  end

  initial begin
    start = 1;
    #40 start = 0;
    repeat (100) @(posedge clk);
    `$display("Time: %d", time);
    #10 $finish;
  end

endmodule

这段代码首先实例化了一个Timer模块，并将其连接到了一个时钟信号、一个复位信号、一个开始信号和一个时间输出端口。

然后在initial块中，首先将时钟信号赋值为0，并启动一个Forever循环以产生10个时间单位的时钟脉冲。接着，在第二个initial块中，将复位信号赋值为1并在20个时间单位后将其赋值为0。最后再一个initial块中，将开始信号赋值为1，并在40个时间单位后将其赋值为0。等待100个时钟周期后，通过$display语句将时间输出，并在额外的10个时间单位后结束仿真过程。

相关问题

用verilog代码实现病房呼叫系统

好的，我可以为您提供一个简单的Verilog代码框架，用于实现病房呼叫系统。请注意，这只是一个框架，您需要根据具体的需求和硬件设计进行修改和完善。

module call_system(
    input clk,
    input rst,
    input [n] call_signal, // 呼叫信号输入
    output [m] alert_signal // 报警信号输出
);

// 定义状态机状态
parameter IDLE = 2'b00; // 空闲状态
parameter TRIGGERED = 2'b01; // 触发状态
parameter ALERT = 2'b10; // 报警状态

reg [1:0] state;
reg [m] alert_reg;

always @(posedge clk) begin
    if (rst) begin
        state <= IDLE;
        alert_reg <= 0;
    end else begin
        case (state)
            IDLE: begin
                // 检测到呼叫信号
                if (call_signal) begin
                    state <= TRIGGERED;
                end
            end
            
            TRIGGERED: begin
                // 持续一段时间后进入报警状态
                if (timer_finished) begin
                    state <= ALERT;
                    alert_reg <= call_signal;
                end
            end
            
            ALERT: begin
                // 报警信号持续输出
                alert_reg <= call_signal;
            end
        endcase
    end
end

assign alert_signal = alert_reg;

endmodule

以上是一个简单的病房呼叫系统的Verilog代码框架，其中包含了一个状态机，用于检测呼叫信号并触发报警信号的输出。您需要根据具体的需求和硬件设计进行修改和完善。

1.用System Verilog书写7位数据位，1位偶校验，波特率为115200bps的uart串行发送端 2. 用SV书写对应的行为模型（接收端），并输出激励中的字节值，奇偶性错误的，输出校验错误 3.编写testcase

1. 以下是用System Verilog书写的7位数据位，1位偶校验，波特率为115200bps的uart串行发送端：

module uart_tx (
    input clk,
    input reset,
    input [6:0] data_in,
    output reg tx_out
);

// 波特率计算
localparam BAUD_RATE = 115200;
localparam BIT_TIME = $floor(1000000000/BAUD_RATE); // 单位：ns

// 发送状态机
typedef enum logic [2:0] {
    IDLE,
    START_BIT,
    DATA_BITS,
    PARITY_BIT,
    STOP_BIT
} TxState;

reg [2:0] state = IDLE;
reg [6:0] data = 7'b0000000;
reg parity = 1'b0;
reg [3:0] bit_cnt = 4'd0;
reg [31:0] bit_timer = 32'd0;

// 计时器
always @(posedge clk) begin
    if (reset) begin
        bit_timer <= 0;
    end else begin
        bit_timer <= bit_timer + 1;
    end
end

// 状态机
always @(posedge clk) begin
    if (reset) begin
        state <= IDLE;
        data <= 7'b0000000;
        parity <= 1'b0;
        bit_cnt <= 4'd0;
        tx_out <= 1'b1;
    end else begin
        case (state)
            IDLE: begin
                if (!tx_out) begin
                    state <= START_BIT;
                    bit_cnt <= 4'd0;
                    bit_timer <= 0;
                end
            end
            START_BIT: begin
                if (bit_timer >= BIT_TIME) begin
                    tx_out <= 1'b0;
                    state <= DATA_BITS;
                    bit_cnt <= 4'd1;
                    bit_timer <= 0;
                end
            end
            DATA_BITS: begin
                if (bit_timer >= BIT_TIME) begin
                    data[bit_cnt-1] <= data_in[bit_cnt-1];
                    parity <= parity ^ data_in[bit_cnt-1];
                    bit_cnt <= bit_cnt + 1;
                    if (bit_cnt == 8) begin
                        state <= PARITY_BIT;
                        bit_cnt <= 4'd0;
                    end else begin
                        bit_timer <= 0;
                    end
                end
            end
            PARITY_BIT: begin
                if (bit_timer >= BIT_TIME) begin
                    tx_out <= parity;
                    state <= STOP_BIT;
                    bit_timer <= 0;
                end
            end
            STOP_BIT: begin
                if (bit_timer >= BIT_TIME) begin
                    tx_out <= 1'b1;
                    state <= IDLE;
                    bit_timer <= 0;
                end
            end
            default: state <= IDLE;
        endcase
    end
end

endmodule

2. 以下是用SV书写的对应的行为模型（接收端），并输出激励中的字节值，奇偶性错误的，输出校验错误：

module uart_rx (
    input clk,
    input reset,
    input rx_in,
    output [6:0] data_out,
    output reg valid,
    output reg parity_error,
    output reg frame_error
);

// 波特率计算
localparam BAUD_RATE = 115200;
localparam BIT_TIME = $floor(1000000000/BAUD_RATE); // 单位：ns

// 接收状态机
typedef enum logic [2:0] {
    IDLE,
    START_BIT,
    DATA_BITS,
    PARITY_BIT,
    STOP_BIT
} RxState;

reg [2:0] state = IDLE;
reg [6:0] data = 7'b0000000;
reg parity = 1'b0;
reg [3:0] bit_cnt = 4'd0;
reg [31:0] bit_timer = 32'd0;

// 计时器
always @(posedge clk) begin
    if (reset) begin
        bit_timer <= 0;
    end else begin
        bit_timer <= bit_timer + 1;
    end
end

// 状态机
always @(posedge clk) begin
    if (reset) begin
        state <= IDLE;
        data <= 7'b0000000;
        parity <= 1'b0;
        bit_cnt <= 4'd0;
        valid <= 1'b0;
        parity_error <= 1'b0;
        frame_error <= 1'b0;
    end else begin
        case (state)
            IDLE: begin
                if (!rx_in) begin
                    state <= START_BIT;
                    bit_cnt <= 4'd0;
                    bit_timer <= 0;
                end
            end
            START_BIT: begin
                if (bit_timer >= BIT_TIME) begin
                    state <= DATA_BITS;
                    bit_cnt <= 4'd1;
                    bit_timer <= 0;
                end
            end
            DATA_BITS: begin
                if (bit_timer >= BIT_TIME) begin
                    data[bit_cnt-1] <= rx_in;
                    parity <= parity ^ rx_in;
                    bit_cnt <= bit_cnt + 1;
                    if (bit_cnt == 8) begin
                        state <= PARITY_BIT;
                        bit_cnt <= 4'd0;
                    end else begin
                        bit_timer <= 0;
                    end
                end
            end
            PARITY_BIT: begin
                if (bit_timer >= BIT_TIME) begin
                    if (rx_in != parity) begin
                        parity_error <= 1'b1;
                    end
                    state <= STOP_BIT;
                    bit_timer <= 0;
                end
            end
            STOP_BIT: begin
                if (bit_timer >= BIT_TIME) begin
                    if (rx_in) begin
                        frame_error <= 1'b1;
                    end else begin
                        data_out <= data;
                        valid <= 1'b1;
                    end
                    state <= IDLE;
                    bit_timer <= 0;
                end
            end
            default: state <= IDLE;
        endcase
    end
end

endmodule

3. 以下是编写的testcase：

module testbench;

// 参数
localparam BAUD_RATE = 115200;
localparam BIT_TIME = $floor(1000000000/BAUD_RATE); // 单位：ns

// 实例化
uart_tx tx (
    .clk(clk),
    .reset(reset),
    .data_in(data_in),
    .tx_out(tx_out)
);

uart_rx rx (
    .clk(clk),
    .reset(reset),
    .rx_in(rx_in),
    .data_out(data_out),
    .valid(valid),
    .parity_error(parity_error),
    .frame_error(frame_error)
);

// 输入
reg clk = 1;
reg reset = 0;
reg [6:0] data_in;
reg [31:0] timer = 0;
reg [31:0] rand_seed = 1;

// 输出
wire tx_out;
wire [6:0] data_out;
wire valid;
wire parity_error;
wire frame_error;

// 生成随机字节
function automatic void gen_byte(ref byte b);
    repeat (8) begin
        b[$] = $urandom(rand_seed) % 2;
    end
endfunction

// 生成随机奇偶校验的字节
function automatic void gen_parity_byte(ref byte b, ref bit p);
    repeat (8) begin
        b[$] = $urandom(rand_seed) % 2;
        p ^= b[$];
    end
    b[$] = p;
endfunction

// 生成随机错误字节（奇偶性错误，数据位错误，停止位错误）
function automatic void gen_error_byte(ref byte b, input bit parity, input bit data, input bit stop);
    repeat (8) begin
        b[$] = $urandom(rand_seed) % 2;
    end
    b[0] = ~b[0] ^ parity;
    if (data) begin
        b[$-1] = ~b[$-1];
    end
    if (stop) begin
        b[$] = ~b[$];
    end
endfunction

// 生成随机字节序列
function automatic void gen_bytes(ref byte [][8] bytes, input int count, input bit parity);
    bit p;
    for (int i = 0; i < count; i++) begin
        gen_parity_byte(bytes[i], p);
        if (parity == 0) begin
            p = ~p;
        end
    end
endfunction

// 生成随机错误字节序列
function automatic void gen_error_bytes(ref byte [][8] bytes, input int count, input bit parity, input bit data, input bit stop);
    bit p;
    for (int i = 0; i < count; i++) begin
        gen_error_byte(bytes[i], parity, data, stop);
    end
endfunction

// 计时器
always @(posedge clk) begin
    timer <= timer + 1;
end

// 时钟
always #5 clk <= ~clk;

// 测试过程
initial begin
    // 测试1：连续发送100个随机字节
    $display("Test 1: send 100 random bytes");
    gen_bytes(data_in, 100, 1);
    repeat (100) begin
        #1;
    end
    repeat (10) begin
        #1;
    end

    // 测试2：发送一个有奇偶校验错误的字节
    $display("Test 2: send a byte with parity error");
    gen_error_bytes(data_in, 1, 1, 0, 0);
    repeat (10) begin
        #1;
    end

    // 测试3：发送一个有数据位错误的字节
    $display("Test 3: send a byte with data error");
    gen_error_bytes(data_in, 1, 0, 1, 0);
    repeat (10) begin
        #1;
    end

    // 测试4：发送一个有停止位错误的字节
    $display("Test 4: send a byte with stop error");
    gen_error_bytes(data_in, 1, 0, 0, 1);
    repeat (10) begin
        #1;
    end

    // 结束
    $finish;
end

endmodule