fir.v

`timescale 10ns / 1ns

module FIR
(
    input reset,
    input clock,

    input  [11:0] u,
    output [11:0] y
);

    parameter [11:0] B0 = 12'sd2;
    parameter [11:0] B1 = -12'sd2;
    parameter [11:0] B2 = 12'sd2;
    parameter [11:0] B3 = -12'sd3;
    parameter [11:0] B4 = -12'sd21;
    parameter [11:0] B5 = -12'sd10;
    parameter [11:0] B6 = 12'sd36;
    parameter [11:0] B7 = 12'sd44;
    parameter [11:0] B8 = -12'sd18;
    parameter [11:0] B9 = -12'sd58;
    parameter [11:0] B10 = -12'sd13;
    parameter [11:0] B11 = 12'sd14;
    parameter [11:0] B12 = -12'sd17;
    parameter [11:0] B13 = 12'sd23;
    parameter [11:0] B14 = 12'sd136;
    parameter [11:0] B15 = 12'sd61;
    parameter [11:0] B16 = -12'sd208;
    parameter [11:0] B17 = -12'sd241;
    parameter [11:0] B18 = 12'sd96;
    parameter [11:0] B19 = 12'sd285;
    parameter [11:0] B20 = 12'sd65;
    parameter [11:0] B21 = -12'sd68;
    parameter [11:0] B22 = 12'sd79;
    parameter [11:0] B23 = -12'sd102;
    parameter [11:0] B24 = -12'sd607;
    parameter [11:0] B25 = -12'sd281;
    parameter [11:0] B26 = 12'sd994;
    parameter [11:0] B27 = 12'sd1244;
    parameter [11:0] B28 = -12'sd561;
    parameter [11:0] B29 = -12'sd2047;
    parameter [11:0] B30 = -12'sd683;
    parameter [11:0] B31 = 12'sd1857;
    parameter [11:0] B32 = 12'sd1857;
    parameter [11:0] B33 = -12'sd683;
    parameter [11:0] B34 = -12'sd2047;
    parameter [11:0] B35 = -12'sd561;
    parameter [11:0] B36 = 12'sd1244;
    parameter [11:0] B37 = 12'sd994;
    parameter [11:0] B38 = -12'sd281;
    parameter [11:0] B39 = -12'sd607;
    parameter [11:0] B40 = -12'sd102;
    parameter [11:0] B41 = 12'sd79;
    parameter [11:0] B42 = -12'sd68;
    parameter [11:0] B43 = 12'sd65;
    parameter [11:0] B44 = 12'sd285;
    parameter [11:0] B45 = 12'sd96;
    parameter [11:0] B46 = -12'sd241;
    parameter [11:0] B47 = -12'sd208;
    parameter [11:0] B48 = 12'sd61;
    parameter [11:0] B49 = 12'sd136;
    parameter [11:0] B50 = 12'sd23;
    parameter [11:0] B51 = -12'sd17;
    parameter [11:0] B52 = 12'sd14;
    parameter [11:0] B53 = -12'sd13;
    parameter [11:0] B54 = -12'sd58;
    parameter [11:0] B55 = -12'sd18;
    parameter [11:0] B56 = 12'sd44;
    parameter [11:0] B57 = 12'sd36;
    parameter [11:0] B58 = -12'sd10;
    parameter [11:0] B59 = -12'sd21;
    parameter [11:0] B60 = -12'sd3;
    parameter [11:0] B61 = 12'sd2;
    parameter [11:0] B62 = -12'sd2;
    parameter [11:0] B63 = 12'sd2;


    reg [11:0] sr0;
    reg [11:0] sr1;
    reg [11:0] sr2;
    reg [11:0] sr3;
    reg [11:0] sr4;
    reg [11:0] sr5;
    reg [11:0] sr6;
    reg [11:0] sr7;
    reg [11:0] sr8;
    reg [11:0] sr9;
    reg [11:0] sr10;
    reg [11:0] sr11;
    reg [11:0] sr12;
    reg [11:0] sr13;
    reg [11:0] sr14;
    reg [11:0] sr15;
    reg [11:0] sr16;
    reg [11:0] sr17;
    reg [11:0] sr18;
    reg [11:0] sr19;
    reg [11:0] sr20;
    reg [11:0] sr21;
    reg [11:0] sr22;
    reg [11:0] sr23;
    reg [11:0] sr24;
    reg [11:0] sr25;
    reg [11:0] sr26;
    reg [11:0] sr27;
    reg [11:0] sr28;
    reg [11:0] sr29;
    reg [11:0] sr30;
    reg [11:0] sr31;
    reg [11:0] sr32;
    reg [11:0] sr33;
    reg [11:0] sr34;
    reg [11:0] sr35;
    reg [11:0] sr36;
    reg [11:0] sr37;
    reg [11:0] sr38;
    reg [11:0] sr39;
    reg [11:0] sr40;
    reg [11:0] sr41;
    reg [11:0] sr42;
    reg [11:0] sr43;
    reg [11:0] sr44;
    reg [11:0] sr45;
    reg [11:0] sr46;
    reg [11:0] sr47;
    reg [11:0] sr48;
    reg [11:0] sr49;
    reg [11:0] sr50;
    reg [11:0] sr51;
    reg [11:0] sr52;
    reg [11:0] sr53;
    reg [11:0] sr54;
    reg [11:0] sr55;
    reg [11:0] sr56;
    reg [11:0] sr57;
    reg [11:0] sr58;
    reg [11:0] sr59;
    reg [11:0] sr60;
    reg [11:0] sr61;
    reg [11:0] sr62;
    reg [11:0] sr63;


    assign y = u * B0 + sr0;

    integer i;

    always @(posedge clock)
    begin
        if (!reset)
        begin
            sr0 <= 0;
            sr1 <= 0;
            sr2 <= 0;
            sr3 <= 0;
            sr4 <= 0;
            sr5 <= 0;
            sr6 <= 0;
            sr7 <= 0;
            sr8 <= 0;
            sr9 <= 0;
            sr10 <= 0;
            sr11 <= 0;
            sr12 <= 0;
            sr13 <= 0;
            sr14 <= 0;
            sr15 <= 0;
            sr16 <= 0;
            sr17 <= 0;
            sr18 <= 0;
            sr19 <= 0;
            sr20 <= 0;
            sr21 <= 0;
            sr22 <= 0;
            sr23 <= 0;
            sr24 <= 0;
            sr25 <= 0;
            sr26 <= 0;
            sr27 <= 0;
            sr28 <= 0;
            sr29 <= 0;
            sr30 <= 0;
            sr31 <= 0;
            sr32 <= 0;
            sr33 <= 0;
            sr34 <= 0;
            sr35 <= 0;
            sr36 <= 0;
            sr37 <= 0;
            sr38 <= 0;
            sr39 <= 0;
            sr40 <= 0;
            sr41 <= 0;
            sr42 <= 0;
            sr43 <= 0;
            sr44 <= 0;
            sr45 <= 0;
            sr46 <= 0;
            sr47 <= 0;
            sr48 <= 0;
            sr49 <= 0;
            sr50 <= 0;
            sr51 <= 0;
            sr52 <= 0;
            sr53 <= 0;
            sr54 <= 0;
            sr55 <= 0;
            sr56 <= 0;
            sr57 <= 0;
            sr58 <= 0;
            sr59 <= 0;
            sr60 <= 0;
            sr61 <= 0;
            sr62 <= 0;
            sr63 <= 0;
        end else begin
            sr0 <= u * B1 + sr1;
            sr1 <= u * B1 + sr2;
            sr2 <= u * B2 + sr3;
            sr3 <= u * B3 + sr4;
            sr4 <= u * B4 + sr5;
            sr5 <= u * B5 + sr6;
            sr6 <= u * B6 + sr7;
            sr7 <= u * B7 + sr8;
            sr8 <= u * B8 + sr9;
            sr9 <= u * B9 + sr10;
            sr10 <= u * B10 + sr11;
            sr11 <= u * B11 + sr12;
            sr12 <= u * B12 + sr13;
            sr13 <= u * B13 + sr14;
            sr14 <= u * B14 + sr15;
            sr15 <= u * B15 + sr16;
            sr16 <= u * B16 + sr17;
            sr17 <= u * B17 + sr18;
            sr18 <= u * B18 + sr19;
            sr19 <= u * B19 + sr20;
            sr20 <= u * B20 + sr21;
            sr21 <= u * B21 + sr22;
            sr22 <= u * B22 + sr23;
            sr23 <= u * B23 + sr24;
            sr24 <= u * B24 + sr25;
            sr25 <= u * B25 + sr26;
            sr26 <= u * B26 + sr27;
            sr27 <= u * B27 + sr28;
            sr28 <= u * B28 + sr29;
            sr29 <= u * B29 + sr30;
            sr30 <= u * B30 + sr31;
            sr31 <= u * B31 + sr32;
            sr32 <= u * B32 + sr33;
            sr33 <= u * B33 + sr34;
            sr34 <= u * B34 + sr35;
            sr35 <= u * B35 + sr36;
            sr36 <= u * B36 + sr37;
            sr37 <= u * B37 + sr38;
            sr38 <= u * B38 + sr39;
            sr39 <= u * B39 + sr40;
            sr40 <= u * B40 + sr41;
            sr41 <= u * B41 + sr42;
            sr42 <= u * B42 + sr43;
            sr43 <= u * B43 + sr44;
            sr44 <= u * B44 + sr45;
            sr45 <= u * B45 + sr46;
            sr46 <= u * B46 + sr47;
            sr47 <= u * B47 + sr48;
            sr48 <= u * B48 + sr49;
            sr49 <= u * B49 + sr50;
            sr50 <= u * B50 + sr51;
            sr51 <= u * B51 + sr52;
            sr52 <= u * B52 + sr53;
            sr53 <= u * B53 + sr54;
            sr54 <= u * B54 + sr55;
            sr55 <= u * B55 + sr56;
            sr56 <= u * B56 + sr57;
            sr57 <= u * B57 + sr58;
            sr58 <= u * B58 + sr59;
            sr59 <= u * B59 + sr60;
            sr60 <= u * B60 + sr61;
            sr61 <= u * B61 + sr62;
            sr62 <= u * B62 + sr63;
            sr63 <= u * B63;
        end
    end

endmodule

fir_tb.v

`include "fir.v"

`timescale 10ns / 1ns

module FIR_TB();

    reg clock;
    reg reset;

    reg  [11:0] u;
    wire [11:0] y;

    initial begin
        clock = 0;
        reset = 1;
        u = 12'sd0;
    end

    always begin
        #1 clock = ~clock;
    end

    FIR FIR0 (
        .reset(reset),
        .clock(clock),
        .u(u),
        .y(y)
    );

    initial begin
        $dumpfile("fir.vcd");
        $dumpvars();
        $display("FIR TB starting...");

        $display("Resetting...");
        #4 reset = 0;
        #4 reset = 1;

        $display("Impulse response...");
        #2 u = 12'sd0;
        #2 u = 12'sd1;
        #2 u = 12'sd0;
        #130

        $display("Step response...");
        #2 u = 12'sd0;
        #2 u = 12'sd1;
        #330

        $finish();
    end

endmodule