FPGA排序-冒泡排序(Verilog版)介紹

在之前的推文中介紹了冒泡排序的實(shí)現(xiàn)，但是分享的代碼使用的是SpinalHDL，最近有好多小伙伴后臺(tái)私信問(wèn)有沒(méi)有Verilog版的代碼。今天就給大家貼出來(lái)，具體原理參考FPGA排序--冒泡排序這篇之前的文章。

仍然以8個(gè)8bit的數(shù)為例來(lái)介紹冒泡排序，因此數(shù)據(jù)的輸入和輸出位寬均為64bit(8*8bit)，使用valid信號(hào)來(lái)標(biāo)識(shí)數(shù)據(jù)有效，整個(gè)實(shí)現(xiàn)采用流水線的方式。

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`timescale?1ns?/?1ps


module bubble(
    input           clk             ,
    input           rst             ,
    input   [63:0]  data_in         ,
    input           data_in_valid   ,
    output  [63:0]  data_out        ,
    output          data_out_valid


);
    reg [ 3:0]  data_in_valid_ff;
    reg [63:0]  data_in_ff[3:0] ;
    reg         v[7:0][7:0]     ;
    reg [ 1:0]  sum_1[7:0][3:0] ;
    reg [ 2:0]  sum_2[7:0][1:0] ;
    reg [ 3:0]  sum_3[7:0]      ;


    reg [7:0]   data_out_temp[7:0] ;
    reg         data_out_valid_temp;


    genvar i;
    genvar j;




    always @(posedge clk ) begin
        if(rst == 1'b1)begin
            data_in_valid_ff <= 4'b0;
        end
        else begin
            data_in_valid_ff <= {data_in_valid_ff[2:0], data_in_valid};
        end
    end


    always @(posedge clk ) begin
        data_in_ff[0] <= data_in;
    end


    generate
        for ( i = 0; i < 3 ; i = i + 1 ) begin : LOOP_DATA_IN
            always @(posedge clk ) begin
                data_in_ff[i+1] <= data_in_ff[i];
            end
        end
    endgenerate


    generate
        for ( i = 0 ; i < 8 ; i = i + 1 ) begin : LOOP_V_I
            for ( j = i ; j < 8 ; j = j + 1) begin : LOOP_V_J
                always @(posedge clk ) begin
                    if(data_in_valid == 1'b1)begin
                        v[i][j] <= data_in[i*8 +: 8] >= data_in[j*8 +: 8];
                        v[j][i] <= data_in[i*8 +: 8] <  data_in[j*8 +: 8];
                    end
                end
            end
        end
    endgenerate


    generate
        for ( i = 0 ; i < 8 ; i = i + 1 ) begin : LOOP_SUM_1_I
            for ( j = 0 ; j < 4 ; j = j + 1) begin : LOOP_SUM_1_J
                always @(posedge clk ) begin
                    if(data_in_valid_ff[0] == 1'b1)begin
                        sum_1[i][j] <= v[i][j*2] + v[i][j*2 + 1];
                    end
                end
            end
        end
    endgenerate


    generate
        for ( i = 0 ; i < 8 ; i = i + 1 ) begin : LOOP_SUM_2_I
            for ( j = 0 ; j < 2 ; j = j + 1) begin : LOOP_SUM_2_J
                always @(posedge clk ) begin
                    if(data_in_valid_ff[1] == 1'b1)begin
                        sum_2[i][j] <= sum_1[i][j*2] + sum_1[i][j*2 + 1];
                    end
                end
            end
        end
    endgenerate


    generate
        for ( i = 0 ; i < 8 ; i = i + 1 ) begin : LOOP_SUM_3_I
            always @(posedge clk ) begin
                if(data_in_valid_ff[2] == 1'b1)begin
                    sum_3[i] <= sum_2[i][0] + sum_2[i][1];
                end
            end
        end
    endgenerate


    always @(posedge clk ) begin : LOOP_DATA_OUT_TEMP_CLK
        integer k;
        for ( k = 0; k < 8; k = k + 1) begin : LOOP_DATA_OUT_TEMP
            if(data_in_valid_ff[3] == 1'b1)begin 
                data_out_temp[sum_3[k]] <= data_in_ff[3][k*8 +: 8];
                data_out_valid_temp     <= 1'b1;
            end
            else begin
                data_out_temp[sum_3[k]] <= 8'd0;
                data_out_valid_temp     <= 1'b0;
            end
        end
    end


    generate
        for ( i = 0 ; i < 8 ; i = i + 1) begin : LOOP_DATA_OUT
            assign data_out[i*8 +: 8] = data_out_temp[i]   ;
            assign data_out_valid     = data_out_valid_temp;
        end
    endgenerate


endmodule

在代碼中用了大量的生成語(yǔ)句，這樣可以降低我們的代碼量，這些生成語(yǔ)句幫我們生成了大量的重復(fù)性電路，我們并不需要有什么擔(dān)心。

仿真代碼：

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`timescale?1ns?/?1ps
module tb_bubble(


    );


    reg clk;
    reg rst;


    reg [7:0] data_in_0;
    reg [7:0] data_in_1;
    reg [7:0] data_in_2;
    reg [7:0] data_in_3;
    reg [7:0] data_in_4;
    reg [7:0] data_in_5;
    reg [7:0] data_in_6;
    reg [7:0] data_in_7;


    wire [63:0] data_in;
    reg         data_in_valid;


    wire [63:0] data_out;
    wire        data_out_valid;


    initial begin
        clk = 1'b0;
        rst = 1'b1;
        #50
        rst = 1'b0;
    end


    always #5 clk = !clk;


    always @(posedge clk ) begin
        if(rst == 1'b1)begin
            data_in_0     <= 8'd0;
            data_in_1     <= 8'd0;
            data_in_2     <= 8'd0;
            data_in_3     <= 8'd0;
            data_in_4     <= 8'd0;
            data_in_5     <= 8'd0;
            data_in_6     <= 8'd0;
            data_in_7     <= 8'd0;
            data_in_valid <= 1'b0;
        end
        else begin
            data_in_0     <= {$random} % 255;
            data_in_1     <= {$random} % 255;
            data_in_2     <= {$random} % 255;
            data_in_3     <= {$random} % 255;
            data_in_4     <= {$random} % 255;
            data_in_5     <= {$random} % 255;
            data_in_6     <= {$random} % 255;
            data_in_7     <= {$random} % 255;
            data_in_valid <= 1'b1;
        end
    end


    assign data_in = {data_in_0, data_in_1, data_in_2, data_in_3, data_in_4, data_in_5, data_in_6, data_in_7};


    bubble u_bubble(
        .clk                (clk           ),
        .rst                (rst           ),
        .data_in            (data_in       ),
        .data_in_valid      (data_in_valid ),
        .data_out           (data_out      ),
        .data_out_valid     (data_out_valid)


    );


endmodule

仿真結(jié)果：

可以看到每個(gè)時(shí)鐘周期輸出8個(gè)排好序的數(shù)字。

消耗的資源如上。如果我們不需要流水輸出的話，使用的資源可以進(jìn)一步進(jìn)行壓縮，這個(gè)就看具體的需求了，資源和性能的平衡。

審核編輯：劉清