鉴频鉴相器verilog代码

以下是一个简单的鉴频鉴相器的 Verilog 代码示例：

module freq_phase_detector (
  input clk,
  input reset,
  input ref_clk,
  output reg phase_locked,
  output reg freq_locked
);

reg [23:0] ref_cnt;
reg [23:0] clk_cnt;
reg [23:0] phase_error;

always @(posedge ref_clk or posedge reset) begin
  if (reset) begin
    ref_cnt <= 0;
  end else begin
    ref_cnt <= ref_cnt + 1;
  end
end

always @(posedge clk or posedge reset) begin
  if (reset) begin
    clk_cnt <= 0;
  end else begin
    clk_cnt <= clk_cnt + 1;
  end
end

always @(posedge clk or posedge ref_clk or posedge reset) begin
  if (reset) begin
    phase_error <= 0;
    phase_locked <= 0;
    freq_locked <= 0;
  end else begin
    phase_error <= ref_cnt - clk_cnt;
    
    if (abs(phase_error) < 10) begin
      phase_locked <= 1;
    end else begin
      phase_locked <= 0;
    end
    
    if (abs(phase_error) < 100) begin
      freq_locked <= 1;
    end else begin
      freq_locked <= 0;
    end
  end
end

endmodule

以上代码实现了一个简单的鉴频鉴相器，可以根据输入的两个时钟信号的相位差和频率差来判断是否锁定。具体实现方法是计算两个时钟信号的计数器值之间的差值，如果差值小于某个阈值，则认为信号已经锁定。