Verilog-数字序列检测器

1、检测数字序列11011

2、代码

`timescale 1ns / 1ps

module digit_sequence_detect(
    input clk,
    input rstn,
    input data_in,
    output detect
    );
     
localparam S0=3'd0,S1=3'd1,S2=3'd2,S3=3'd3,S4=3'd4,S5=3'd5;
reg [2:0] state,next_state;
reg detect_reg;

always @(posedge clk or negedge rstn) begin
    if(!rstn) state <= 3'd0;
    else state <= next_state;
end

always @(*) begin
    case(state)
        S0:if(data_in==1'b1) next_state = S1;
            else next_state = S0;
        S1:if(data_in==1'b1) next_state = S2;
            else next_state = S0;
        S2:if(data_in==1'b0) next_state = S3;
            else next_state=S2;
        S3:if(data_in==1'b1) next_state = S4;
            else next_state = S0;
        S4:if(data_in==1'b1) next_state = S5;
            else next_state = S0;
        S5:if(data_in==1'b1) next_state = S1;
            else next_state = S0;
        default:next_state = S0;
    endcase
end

always @(*) begin
    if(state==S5) detect_reg = 1'b1;
    else detect_reg = 1'b0;
end
assign detect = detect_reg;

endmodule

3、测试激励

`timescale 1ns / 1ps

module digit_sequence_detect_tb;

    // Inputs
    reg clk;
    reg rstn;
    reg data_in;

    // Outputs
    wire detect;
    
    reg [15:0] digit_sequence;
    integer i;

    // Instantiate the Unit Under Test (UUT)
    digit_sequence_detect uut (
        .clk(clk), 
        .rstn(rstn), 
        .data_in(data_in), 
        .detect(detect)
    );
    
    

    initial begin
        // Initialize Inputs
        clk = 0;
        rstn = 0;
        data_in = 0;
        digit_sequence = 16'b11011011_00111011;

        // Wait 100 ns for global reset to finish
        #100;
        rstn = 1;
        
        for(i=15;i>=0;i=i-1) begin
            @(negedge clk) begin
                data_in = digit_sequence[i];
            end
        end
        
        
        
        // Add stimulus here

    end
    
    always #20 clk = ~clk;
      
endmodule

4、波形

　　

 5、连续检测代码只需更改S5状态的跳转逻辑

        S5:if(data_in==1'b1) next_state = S2;    //连续检测
            else next_state = S3;

波形：