以下是用 Verilog 实现一个 5bit 序列检测器的代码：
module five_bit_sequence_detector(input clk,input reset,input [4:0] in,output reg detected
);// 定义状态参数localparam IDLE = 4'b0000;localparam STATE1 = 4'b0001;localparam STATE2 = 4'b0010;localparam STATE3 = 4'b0011;localparam STATE4 = 4'b0100;localparam DETECTED_STATE = 4'b0101;reg [3:0] current_state;reg [3:0] next_state;always @(posedge clk or posedge reset) beginif (reset) begincurrent_state <= IDLE;detected <= 1'b0;end else begincurrent_state <= next_state;if (current_state == DETECTED_STATE)detected <= 1'b1;elsedetected <= 1'b0;endendalways @(*) begincase (current_state)IDLE:if (in == 5'b00001)next_state = STATE1;elsenext_state = IDLE;STATE1:if (in == 5'b00010)next_state = STATE2;elsenext_state = IDLE;STATE2:if (in == 5'b00100)next_state = STATE3;elsenext_state = IDLE;STATE3:if (in == 5'b01000)next_state = STATE4;elsenext_state = IDLE;STATE4:if (in == 5'b10000)next_state = DETECTED_STATE;elsenext_state = IDLE;DETECTED_STATE:if (in == 5'b10000)next_state = DETECTED_STATE;elsenext_state = IDLE;default:next_state = IDLE;endcaseendendmodule
这个序列检测器检测特定的 5bit 序列 “00001”、“00010”、“00100”、“01000”、“10000”。当输入序列与这个特定序列匹配时，输出 detected 被置为高电平。状态机从初始状态 IDLE 开始，根据输入逐步进入不同的状态，直到检测到完整序列进入 DETECTED_STATE。如果在任何状态下输入不匹配预期序列，状态机将回到 IDLE 状态重新开始检测。
