基于FPGA的实时图像边缘检测系统设计（附主要代码）下篇

大侠好，欢迎来到FPGA技术江湖，江湖偌大，相见即是缘分。大侠可以关注FPGA技术江湖，在“闯荡江湖”、"行侠仗义"栏里获取其他感兴趣的资源，或者一起煮酒言欢。

今天给大侠带来基于FPGA的实时图像边缘检测系统设计，由于篇幅较长，分三篇。今天带来第三篇，下篇，话不多说，上货。

这里也超链接了上篇和中篇，方便各位大侠参考学习。

基于FPGA的实时图像边缘检测系统设计（上）

基于FPGA的实时图像边缘检测系统设计（中）

随着科学技术的高速发展，FPGA在系统结构上为数字图像处理带来了新的契机。图像中的信息并行存在，因此可以并行对其施以相同的操作，使得图像处理的速度大大提高，这正好适合映射到FPGA架构中用硬件算法得以实现。

本篇阐述了基于FPGA设计一个能够实时采集、实时处理并实时显示的数字图像处理系统的设计思想和流程，分析了摄像头接口的时序；阐述了图像信息的捕获原理；详细介绍了图像边缘检测部分各模块的功能；重点介绍了具有去噪功能的中值滤波模块的设计；简单描述了边缘检测算子的选用；系统的介绍了SDRAM的工作原理以及控制方式；介绍了VGA时序；最后针对整个系统做了验证和总结，包括仿真波形的验证以及板级验证。

该系统基于实体FPGA开发板实现了图像数据的实时采集、实时边缘检测和实时显示，运行稳定，实时性能较高，从而也表明FPGA确实具有海量数据高速传输的能力。

本篇为本人当年的毕业设计部分整理，各位大侠可依据自己的需要进行阅读，参考学习。

第三篇内容摘要：本篇会介绍系统验证、结论以及各个模块主要代码，包括图像实时采集模块的主要代码，图像实时捕获模块的主要代码，中值滤波模块的主要代码，边缘检测模块的主要代码，图像缓存模块的主要代码，图像实时显示模块的主要代码等相关内容。

五、系统验证

在本系统设计过程中，我以自顶向下的层次化设计思想为主进行系统的顶层架构设计，明确各模块的功能以及各模块之间的握手关系，之后分模块编写代码并加以验证，调试代码使得各模块功能得以实现，最后基于顶层模块进行仿真验证，如图5-1和5-2为系统顶层模块的仿真波形，其中图5-1为全局波形，图5-2为局部放大的波形。

图5-1 系统顶层模块的全局仿真波形

 图5-2 系统顶层模块的局部仿真波形

随后连接FPGA开发实验板并更新其驱动程序，按照开发板的配置文件分配引脚，全编译通过后下板进行板级测试。本系统验证时所采用的开发板是实体FPGA开发板。

实体FPGA开发板采用的是Altera Cyclone IV代系列的EP4CE10E22C8N芯片。该开发板是一款FPGA图像开发板，其核心芯片EP4CE10E22C8N拥有6272个逻辑单元和150个IO引脚，开发板上配置有VGA、USB、CMOS接口、SDRAM、按键、LED等很多种外部设备，可以作为本系统设计验证的硬件工具。

实体FPGA开发板的主要参数如下表6-1所示。

表5-1 FPGA开发板的主要参数

下板结果表明我所设计的数字图像边缘检测系统的功能已经实现，能够实时采集图像、实时处理并实时显示，这里截取的是图片，现实场景显示可以根据摄像头的移动实时显示。

六、结论

本系统设计中，我基于FPGA驱动的主要设备如下：型号为Ov7725的摄像头；具有通用性的VGA接口。同时，我研究了相关的边缘检测算法，为了数据处理结果更加准确，我还根据系统需要进行了图像数据的预处理操作：先将彩色图像转换成为灰度文件；接着采用中值滤波技术对采集到的图像数据进行了有效去噪。通过本系统的设计，我深刻理解了基于FPGA驱动外部设备的基本原理，掌握了基于FPGA、运用Verilog语言驱动外部设备和实现算法的能力，感受到了FPGA的先进，也进一步确定了自己的发展方向。在进行系统验证时，基于FPGA开发板实现了图像数据的实时采集、实时边缘检测和实时显示，系统性能良好，实时性能较高，结果证明FPGA能够轻松实现海量数据的高速传输。

附：部分主要代码

图像实时采集模块的主要代码：

1  module sccb_config_ctrl( 2              clk,          //24Mhz输入时钟3              rst_n,        //系统复位4              scl,          //iic的时钟线5              sda,              //iic的数据线6              config_done   //配置完成标志7          );8      //系统输入9   input clk;  //外部输入时钟24Mhz10    input rst_n; //系统复位11    //系统输出12    output reg scl;       //iic的时钟线13    output reg config_done;       //配置完成标志14 15    16    inout sda;                //iic的数据线17    18    reg sda_buffer;   //写入数据的中间寄存器19    reg flag;         //控制系统是否占有总线控制权20  reg [7:0] lut_cnt;  //指针寄存器计数器21  reg [15:0] lut_data; //寄存器地址和配置数据22  reg [3:0] s;23    24    assign sda = (flag) ? sda_buffer : 1'bz;//当flag为高电平时，系统拥有总线控制权25                                            //并发送sda_buffer中的数据。当flag为低电平时，26                                            //释放总线。27                                                          28  //----------延时1ms计数器-----------------29  reg [31:0] delay_cnt;30  reg delay_done;31  32  always @ (posedge clk or negedge rst_n)33  begin34      if(!rst_n)35          begin36              delay_done <= 0;37              delay_cnt <= 0;38          end39      else if(delay_cnt == 20000) //2380940          delay_done <= 1;41      else42          begin43              delay_cnt <= delay_cnt + 1;44              delay_done <= 0;45          end46  end47  48  //----------------分频产生400Khz时钟clk_sys---------- 49    reg [7:0] count;//计数器50    reg clk_sys;//系统时钟51  reg [5:0] state;//状态寄存器52 53    always @ (posedge clk or negedge rst_n)54    begin55        if (!rst_n)56            begin57                clk_sys <= 1'b1;58                count <= 8'd0;59            end60        else61            if (count < 100)//分频成为近200K的时钟62                count <= count + 1;63            else64                begin65                    count <= 8'd0;66                    clk_sys <= ~clk_sys;67                end68    end  69 70  //------------------输出scl-------------71    always @ (negedge clk_sys or negedge rst_n)72    begin73        if (!rst_n)74            begin75                scl <= 1'b1;//复位时，scl为高76            end77        else78            begin79                if(config_done == 1 || delay_done == 0)//当总线忙的时候，scl为近400K的时钟80                    scl <= 1;81                else82                    scl <= ~scl;//空闲时，scl为高83            end84    end85 86    reg [3:0] cnt;//发送或者接收数据的个数87    reg [15:0] memory;//发送或者接受数据的中间寄存器88 89  always @ (posedge clk_sys or negedge rst_n)90    begin91         if (!rst_n)92             begin93                 config_done <= 0;94                 flag <= 1'b1;       //复位时，系统获得总线的控制权95                 sda_buffer <= 1'b1; //向iic的数据线上发送高电平96                 state <= 0;97                   cnt <= 0;98                   memory <= 16'd0;99                   lut_cnt <= 2;100                  s <= 0;101            end102        else    103            case(state)104              0 :if(scl)105                      begin106                      if(delay_done)//延时标志信号拉高107                          begin108                              sda_buffer <= 1'b0; //发送启动信号109                              state <= 1;110                              memory <= 16'h0042;//准备ID地址111                          end112                      else113                          state <= 0;114                   end115                  else116                     state <= 0;117                    118              1 :if((scl == 0) && (cnt < 8))//发送ID地址119                     begin120                         sda_buffer <= memory[7];121                         cnt <= cnt + 1;122                         memory = {memory[14:0],memory[15]};123                         state <= 1;124                     end125                 else126                     begin127                         if ((scl == 0) && (cnt == 8))128                             begin129                                 cnt <= 0;130                                 flag <= 0;//释放总线控制权131                                 state <= 2;132                             end133                         else134                             begin135                                 state <= 1;136                             end137                     end138                                   139                 2 : 140                 if(scl)//在SCL高电平期间接收数据141                         begin142                             if(!sda)//检测应答信号143                                 begin 144                                     state <= 3;145                                     memory <= lut_data;//指针寄存器地址146                                 end147                             else148                                 begin149                                     state <= 0;150                                 end151                         end152                     else153                         state <= 2;154                         155               3 : if((scl == 0) && (cnt < 8)) //发送指针寄存器地址156                      begin157                          flag <= 1;//获得总线控制权158                          sda_buffer <= memory[15];159                          cnt <= cnt + 1;160                          memory = {memory[14:0],memory[15]};161                          state <= 3;162                      end163                   else164                       begin165                           if ((scl == 0) && (cnt == 8))166                               begin167                                   cnt <= 0;168                                   flag <= 0;//释放总线控制权169                                   state <= 4;170                               end171                           else172                               begin173                                   state <= 3;174                               end175                        end176177              4 :178                 if(scl)179                     begin180                         if(!sda)//检测应答信号181                             begin182                                     state <= 5;183                             end184                         else185                                 begin186                                     state <= 0;187                                 end188                     end189                             190               5 : if((scl == 0) && (cnt < 8))//发送八位控制字191                     begin192                         flag <= 1; //获得总线控制权193                         sda_buffer <= memory[15];194                         cnt <= cnt + 1;195                         memory <= {memory[14:0],memory[15]};196                         state <= 5;197                     end198                 else199                     begin200                         if ((scl == 0) && (cnt == 8))201                             begin202                                 cnt <= 0;203                                 flag <= 0; //释放总线控制权204                                 state <= 6;205                                         lut_cnt <= lut_cnt + 1; //指针寄存器+1206                             end207                         else208                             begin209                                 state <= 5;210                             end211                     end212                                   213              6 :  214                 if(scl) //在SCL高电平期间，接收ACK215                     begin216                         if(!sda)//检测应答信号217                             begin218                                 state <= 7;219                             end220                         else221                             begin222                                 state <= 0;223                             end224                     end225             226              7 : if (scl == 0)227                        begin 228                                  flag <= 1;     229                            sda_buffer <= 0;//拉低数据线（为发送停止信号做准备）230                            state <= 8;231                        end232                     else233                        state <= 7;234235              8 : if (scl == 1)  //发送停止信号236                         begin237                             sda_buffer <= 1;238                             begin239                                 if (s == 8)240                                     begin241                                         if(lut_cnt < 70)242                                             begin243                                                 state <= 0;244                                                 s <= 0;245                                             end246                                         else247                                             config_done <= 1;  //配置完成248                                     end249                                 else250                                     s <= s + 1;251                             end252                      end253                  else254                     state <= 8;255256                default : state <= 0;257                endcase258   end259  260 always @ (*)261 begin262     case (lut_cnt)263     //  OV7725 : VGA RGB565 Config264     //Read Data Index265     //  0 :     LUT_DATA    =   {8'h0A, 8'h77}; //Product ID Number MSB (Read only)266     //  1 :     LUT_DATA    =   {8'h0B, 8'h21}; //Product ID Number LSB (Read only)267     0 :     lut_data    =   {8'h1C, 8'h7F}; //Manufacturer ID Byte - High (Read only)268     1 : lut_data    =   {8'h1D, 8'hA2}; //Manufacturer ID Byte - Low (Read only)269     //Write Data Index270     2   :   lut_data    =   {8'h12, 8'h80}; // BIT[7]-Reset all the Reg 271     3   :   lut_data    =   {8'h3d, 8'h03}; //DC offset for analog process272     4   :   lut_data    =   {8'h15, 8'h02}; //COM10: href/vsync/pclk/data reverse(Vsync H valid)273     5   :   lut_data    =   {8'h17, 8'h22}; //VGA:  8'h22;  QVGA:   8'h3f;274     6   :   lut_data    =   {8'h18, 8'ha4}; //VGA:  8'ha4;  QVGA:   8'h50;275     7   :   lut_data    =   {8'h19, 8'h07}; //VGA:  8'h07;  QVGA:   8'h03;276     8   :   lut_data    =   {8'h1a, 8'hf0}; //VGA:  8'hf0;  QVGA:   8'h78;277     9   :   lut_data    =   {8'h32, 8'h00}; //HREF  / 8'h80278     10  :   lut_data =  {8'h29, 8'hA0}; //VGA:  8'hA0;  QVGA:   8'hF0279     11  :   lut_data =  {8'h2C, 8'hF0}; //VGA:  8'hF0;  QVGA:   8'h78280     //如果不使用内部PLL，这个命令是无效的281     12  :   lut_data    =   {8'h0d, 8'h41}; //Bypass PLL 00:0 01:4x 10:6x 11:8x282     13  :   lut_data    =   {8'h11, 8'h01}; //CLKRC,Finternal clock = Finput clk*PLL multiplier/[(CLKRC[5:0]+1)*2] = 25MHz*4/[(x+1)*2]283                                             //00: 50fps, 01:25fps, 03:12.5fps   (50Hz Fliter)284     14  :   lut_data    =   {8'h12, 8'h06}; //BIT[6]:   0:VGA; 1;QVGA285                                             //BIT[3:2]: 01:RGB565286                                             //VGA:  00:YUV; 01:Processed Bayer RGB; 10:RGB; 11:Bayer RAW; BIT[7]-Reset all the Reg  287     15 :    lut_data    =   {8'h0C, 8'h10}; //COM3: Bit[7:6]:Vertical/Horizontal mirror image ON/OFF, Bit[0]:Color bar; Default:8'h10288     //DSP control289     16 :    lut_data    =   {8'h42, 8'h7f}; //BLC Blue Channel Target Value, Default: 8'h80290     17 :    lut_data    =   {8'h4d, 8'h09}; //BLC Red Channel Target Value, Default: 8'h80291     18  :   lut_data    =   {8'h63, 8'hf0}; //AWB Control292     19  :   lut_data    =   {8'h64, 8'hff}; //DSP_Ctrl1:293     20  :   lut_data    =   {8'h65, 8'h00}; //DSP_Ctrl2:    294     21  :   lut_data    =   {8'h66, 8'h00}; //{COM3[4](0x0C), DSP_Ctrl3[7]}:00:YUYV;    01:YVYU;    [10:UYVY]   11:VYUY 295     22 :    lut_data    =   {8'h67, 8'h00}; //DSP_Ctrl4:00/01: YUV or RGB; 10: RAW8; 11: RAW10  296     //AGC AEC AWB297     23  :   lut_data    =   {8'h13, 8'hff};298     24  :   lut_data    =   {8'h0f, 8'hc5};299     25  :   lut_data    =   {8'h14, 8'h11};300     26  :   lut_data    =   {8'h22, 8'h98}; //Banding Filt er Minimum AEC Value; Default: 8'h09301     27  :   lut_data    =   {8'h23, 8'h03}; //Banding Filter Maximum Step302     28  :   lut_data    =   {8'h24, 8'h40}; //AGC/AEC - Stable Operating Region (Upper Limit)303     29  :   lut_data    =   {8'h25, 8'h30}; //AGC/AEC - Stable Operating Region (Lower Limit)304     30  :   lut_data    =   {8'h26, 8'ha1}; //AGC/AEC Fast Mode Operating Region305     31  :   lut_data    =   {8'h2b, 8'h9e}; //TaiWan: 8'h00:60Hz Filter; Mainland: 8'h9e:50Hz Filter306     32  :   lut_data    =   {8'h6b, 8'haa}; //AWB Control 3307     33  :   lut_data    =   {8'h13, 8'hff}; //8'hff: AGC AEC AWB Enable; 8'hf0: AGC AEC AWB Disable;308     //matrix sharpness brightness contrast UV   309     34 :    lut_data    =   {8'h90, 8'h0a}; 310     35 :    lut_data    =   {8'h91, 8'h01};311     36 :    lut_data    =   {8'h92, 8'h01};312     37 :    lut_data    =   {8'h93, 8'h01};313     38 :    lut_data    =   {8'h94, 8'h5f};314     39 :    lut_data    =   {8'h95, 8'h53};315     40 :    lut_data    =   {8'h96, 8'h11};316     41 :    lut_data    =   {8'h97, 8'h1a};317     42 :    lut_data    =   {8'h98, 8'h3d};318     43 :    lut_data    =   {8'h99, 8'h5a};319     44 :    lut_data    =   {8'h9a, 8'h1e};320     45 :    lut_data    =   {8'h9b, 8'h3f}; //Brightness 321     46 :    lut_data    =   {8'h9c, 8'h25};322     47 :    lut_data    =   {8'h9e, 8'h81}; 323     48 :    lut_data    =   {8'ha6, 8'h06};324     49 :    lut_data    =   {8'ha7, 8'h65};325     50 :    lut_data    =   {8'ha8, 8'h65};326     51 :    lut_data    =   {8'ha9, 8'h80};327     52 :    lut_data    =   {8'haa, 8'h80};328     //Gamma correction329     53 :    lut_data    =   {8'h7e, 8'h0c};330     54 :    lut_data    =   {8'h7f, 8'h16}; //331     55 :    lut_data    =   {8'h80, 8'h2a};332     56 :    lut_data    =   {8'h81, 8'h4e};333     57 :    lut_data    =   {8'h82, 8'h61};334     58 :    lut_data    =   {8'h83, 8'h6f};335     59 :    lut_data    =   {8'h84, 8'h7b};336     60 :    lut_data    =   {8'h85, 8'h86};337     61 :    lut_data    =   {8'h86, 8'h8e};338     62 :    lut_data    =   {8'h87, 8'h97};339     63 :    lut_data    =   {8'h88, 8'ha4};340     64 :    lut_data    =   {8'h89, 8'haf};341     65 :    lut_data    =   {8'h8a, 8'hc5};342     66 :    lut_data    =   {8'h8b, 8'hd7};343     67 :    lut_data    =   {8'h8c, 8'he8};344     68 :    lut_data    =   {8'h8d, 8'h20};345     //Others346     69  :   lut_data    =   {8'h0e, 8'h65};//night mode auto frame rate control347     default : lut_data  =   {8'h1C, 8'h7F};348     endcase349 end350 351 endmodule

图像实时捕获模块的主要代码：

1  module coms_capture_rgb565(clk_cmos, rst_n, pclk, vsync, href, din, xclk,2       frame_data, frame_clk, frame_href, frame_vsync, cmos_fps_rate);3   4   input clk_cmos; //24Mhz驱动时钟输入5   input rst_n;6   input pclk;      //输入的像素时钟7   input vsync;     //输入场同步信号8   input href;      //输入的行同步信号9   input [7:0] din; //输入的像素数据10  11  output xclk;        //输出的CMOS Sensor的驱动时钟 24Mhz12  output frame_clk; //输出拼接后的像素数据的时钟13  output [15:0] frame_data;  //输出拼接后的像素数据14  output frame_href;   //输出同步的行同步信号15  output frame_vsync;  //输出同步的场同步信号16  output reg cmos_fps_rate;  //输出帧率17  18  assign xclk = clk_cmos;19 20  //-------------检测场、行同步信号------------21  reg href_r, vsync_r;22  always @(posedge pclk or negedge rst_n)23  begin24      if (!rst_n)25          begin26              href_r <= 1;27              vsync_r <= 1;28          end29      else30          begin31              href_r <= href;32              vsync_r <= vsync;33          end34  end35  //行同步信号由低电平变为高电平时，说明数据有效36  assign pose_href = (~href_r) & href; 37  //场同步信号由高电平变为低电平时，说明一帧数据接收完毕38  assign nege_vsync = vsync_r & (~vsync);39 40  //----------延时10帧产生一个标志编号----------41  reg frame_cnt_end; //延时10帧数据结束标志42  reg [3:0] frame_cnt;         //帧计数器43  always @(posedge pclk or negedge rst_n)44  begin45      if(!rst_n)46          begin47              frame_cnt <= 0;48              frame_cnt_end <= 0;49          end50      else if (frame_cnt == 10)51          frame_cnt_end <= 1;52      else if(nege_vsync)53          frame_cnt <= frame_cnt + 1;54      else55          frame_cnt <= frame_cnt;56  end57 58  reg [15:0] din_buffer2;59  reg [7:0] din_buffer1;60  reg byte_flag;61  reg [10:0] cnt;62  always @(posedge pclk or negedge rst_n)63  begin64      if(!rst_n)65          begin66              byte_flag <= 0;67              din_buffer1 <= 0;68              din_buffer2 <= 0;69              cnt <= 0;70          end71      else if(href)   72          begin73              cnt <= cnt  + 1;74              din_buffer1 <= din;75              if(cnt >= 1278)76                  byte_flag <= 0;77              else78                  byte_flag <= ~byte_flag;79              80              if(byte_flag == 1)81                  din_buffer2 <= {din_buffer1,din};   82              else83                  din_buffer2 <= din_buffer2;84          end85      else86          begin87              byte_flag <= 0;88              din_buffer1 <= 0;89              din_buffer2 <= din_buffer2;90              cnt <= 0;91          end92  end93  94  reg byte_flag_r;95  always@(posedge pclk or negedge rst_n)96  begin97      if(!rst_n)98          byte_flag_r <= 0;99      else100         byte_flag_r <= byte_flag;101 end102 103 assign frame_data = frame_cnt_end & href ? din_buffer2 : 0;104 assign frame_clk = frame_cnt_end ? byte_flag_r : 0;105 assign frame_vsync = frame_cnt_end ? vsync_r : 1'b0;106 assign frame_href = frame_cnt_end ? href_r : 1'b0;  107108 reg [27:0] delay_cnt;109 always@(posedge pclk or negedge rst_n)110 begin111     if(!rst_n)112         delay_cnt <= 0;113     else if(delay_cnt < 48000000 - 1'b1)114         delay_cnt <= delay_cnt + 1'b1;115     else116         delay_cnt <= 0;117 end118 wire    delay_2s = (delay_cnt == 48000000 - 1'b1) ? 1'b1 : 1'b0;119 120 reg [8:0] cmos_fps_cnt;121 always @(posedge pclk or negedge rst_n)122 begin123     if(!rst_n)124         begin125             cmos_fps_cnt <= 0;126             cmos_fps_rate <= 0;127         end128     else if(delay_2s == 1'b0)129         begin130             cmos_fps_cnt <= nege_vsync ? cmos_fps_cnt + 1'b1 : cmos_fps_cnt;131             cmos_fps_rate <= cmos_fps_rate;132         end133     else134         begin135             cmos_fps_cnt <= 0;136             cmos_fps_rate <= cmos_fps_cnt[8:1];137         end138 end139 140 endmodule

中值滤波模块的主要代码：

1  module zhongzhilvbo (clk, rst_n, data_in, fifo_empty, data_out, wrreq, rdreq);2  3   input clk;4   input rst_n;5   input [23:0] data_in;6   input fifo_empty;7   8   output [7:0] data_out;9   output reg wrreq;10  output reg rdreq;11  12  reg [7:0] data [8:0];13  wire [7:0] data_n[8:0];14  reg shift;15  16  assign data_out = data_n[4];17  18  always @ (posedge clk or negedge rst_n)19      begin20          if (!rst_n)21              begin22                  data [8] <= 0; 23                  data [7] <= 0; 24                  data [6] <= 0; 25                  data [5] <= 0; 26                  data [4] <= 0; 27                  data [3] <= 0; 28                  data [2] <= 0; 29                  data [1] <= 0;30                  data [0] <= 0;31              end32          else33              begin34                  if (shift)35                      begin36                          data[8] <= data[5];37                          data[7] <= data[4];38                          data[6] <= data[3];39                          data[5] <= data[2];40                          data[4] <= data[1];41                          data[3] <= data[0];42                          data[2] <= data_in[23:16];43                          data[1] <= data_in[15:8];44                          data[0] <= data_in[7:0];45                      end46              end47      end48  49  reg compara_rst_n;50  genvar i;51  reg [7:0] temp;52  reg temp_rst_n;53  reg [3:0] count;54  55  always @ (posedge clk or negedge temp_rst_n)56      begin57          if (!temp_rst_n)58              begin59                  temp <= data [8];60                  count <= 0;61              end62          else                        63              begin64                  temp <= data[count];65                  count <= count + 1;66              end67      68      end69  generate 70      for (i = 0; i < 9; i = i + 1)71          begin : compara72              if (i == 0)73                  begin74                      comparaer u1(.clk(clk), .rst_n(compara_rst_n), .ex_data(temp), .up_data(8'hff), .self_data(data_n[i]));75                  end76              else77                  begin78                      comparaer comparaer(.clk(clk), .rst_n(compara_rst_n), .ex_data(temp), .up_data(data_n[i-1]), .self_data(data_n[i]));79                  end80          end81  endgenerate82  83  reg [2:0] state;84  reg [3:0] cnt;85  86  always @ (posedge clk or negedge rst_n)87      begin88          if (!rst_n)89              begin90                  rdreq <= 0;91                  compara_rst_n <= 0;92                  wrreq <= 0;93                  state <= 0;94                  shift <= 0;95                  cnt <= 0;96                  temp_rst_n <= 0;97              end98          else99              begin100                 case (state)101                     0 : begin102                             if (fifo_empty)103                                 begin104                                     state <= 0;105                                     wrreq <= 0;106                                     compara_rst_n <= 0;107                                 end108                             else109                                 begin110                                     state <= 1;111                                     rdreq <= 1;112                                     wrreq <= 0;113                                     compara_rst_n <= 0;114                                 end115                         end116                         117                     1 : begin118                             rdreq <= 0;119                             shift <= 1;120                             state <= 2;121                         end122                         123                     2 : begin124                             shift <= 0;125                             temp_rst_n <= 1;126                             state <= 3;127                         end128                     129                     3 : begin130                             if (cnt < 8)131                                 begin132                                     cnt <= cnt + 1;133                                     compara_rst_n <= 1;134                                     state <= 3;135                                 end136                             else137                                 begin138                                     cnt <= 0;139                                     temp_rst_n <= 0;140                                     state <= 4;141                                 end142                         end143                     144                     4 : begin145                             wrreq <= 1;146                             state <= 0;147                         end148                 149                 endcase150             end151     end152 endmodule

边缘检测模块的主要代码：

1  module sob (clk, rst_n, data, result, fifo_wr, shift_en);2   3   input clk;4   input rst_n;5   input [23:0] data;6   input shift_en;7   8   output reg [7:0] result;9   output reg fifo_wr;10  11  12  reg [7:0]   O[-1:1][-1:1];13  reg signed  [10:0]  Dx, Dy;14  15  function [10:0] abs ( input signed [10:0] x);16      abs = x >=0 ? x : -x ;        //   取x的绝对值17  endfunction18  19  always @ (posedge clk or negedge rst_n)20      begin21          if (!rst_n)22              begin23                  result <= 8'd0;24                  Dx <= 0;25                  Dy <= 0;26              end27          else28              begin29                  if ( shift_en )  30                      begin31                          result <= (abs(Dx) + abs(Dy))>>3 ;// 右移三位实现除以8的运算32                          Dx  <= -$signed({3'b000, O[-1][-1]})    //-1* O[-1][-1]33                                  +$signed({3'b000, O[-1][+1]})   //+1* O[-1][+1]34                                  -($signed({3'b000, O[ 0][-1]})  //-2* O[ 0][-1]35                                  <<1)36                                  +($signed({3'b000, O[ 0][+1]})  //+2* O[ 0][+1]37                                  <<1)        38                                  -$signed({3'b000, O[+1][-1]})   //-1* O[+1][-1]39                                  +$signed({3'b000, O[+1][+1]});  //+1* O[+1][+1]40                          Dy  <= $signed({3'b000, O[-1][-1]}) //+1* O[-1][-1]41                                  +($signed({3'b000, O[-1][ 0]})  //+2* O[-1][0]42                                  <<1)        43                                  +$signed({3'b000, O[-1][+1]})   //+1* O[-1][+1]44                                  -$signed({3'b000, O[+1][-1]})//-1* O[+1][-1]45                                  -($signed({3'b000, O[+1][ 0]})  //-2* O[+1][ 0]46                                  <<1)    47                                  -$signed({3'b000, O[+1][+1]});  //-1* O[+1][+1]48                          O[-1][-1]   <=  O[-1][0];49                          O[-1][ 0]   <=  O[-1][+1];50                          O[-1][+1]   <=  data[23:16];51                          O[ 0][-1]   <=  O[0][0];                52                          O[ 0][ 0]   <=  O[0][+1];53                          O[ 0][+1]   <=  data[15:8];54                          O[+1][-1]   <=  O[+1][0];55                          O[+1][ 0]   <=  O[+1][+1];56                          O[+1][+1]   <=  data[7:0];57              end58          end59      end60 61  62 63  reg [2:0] state;64  65  always @ (posedge clk or negedge rst_n) 66      begin67          if (!rst_n)68              begin69                  fifo_wr <= 1'b0;70                  state <= 0;71              end72          else73              begin74                  case (state)75                      0 : begin76                              if (shift_en)77                                  begin78                                      state <= 2;79                                      fifo_wr <= 0;80                                  end81                              else82                                  begin83                                      state <= 0;84                                      fifo_wr <= 0;85                                  end86                      end87                      88                      1 : begin89                                  if (shift_en)90                                      begin91                                          fifo_wr <= 1'b1;92                                      end93                                  else94                                      fifo_wr <= 0;95                          end96                      97                      2 : state <= 3;98                      99                      3 : state <= 4;100                     101                     4 : state <= 1;102                     103                     default : state <= 0;104                     105                 endcase106             end107     end108     109 endmodule

图像缓存模块的主要代码：

1  `include "sdram_head.v"2  3  module sdr_fsm(soft_rst_n, sys_clk, init_done, ref_done, rd_done, wr_done, ref_time, mux_sel,4           init_rst_n, ref_rst_n, rd_rst_n, wr_rst_n, time_rst_n, int_addr,5            local_rdreq, local_wrreq, local_ready,wr_ddr,rd_ddr,rd_finish, wr_finish,local_finish);6  7   input soft_rst_n;8   input sys_clk;9   input init_done;10  input ref_done;11  input rd_done;12  input wr_done;13  input [9:0] ref_time;14  input [24:0] wr_ddr;15  input [24:0] rd_ddr;16  17 //   input [24:0] local_addr;18 //   output reg [31:0] local_rdata;19 //   input [31:0] local_wdata;20  input local_rdreq, local_wrreq;21  output reg local_ready,local_finish;22  output reg rd_finish;23  output reg wr_finish;24  25  output reg [1:0] mux_sel;26  output reg init_rst_n;27  output reg ref_rst_n;28  output reg rd_rst_n;29  output reg wr_rst_n;30  output reg time_rst_n;31 //   output reg [31:0] wr_data;32  output reg [24:0] int_addr;33  34  localparam s0 = 3'b000;35  localparam s1 = 3'b001;36  localparam s2 = 3'b010;37  localparam s3 = 3'b011;38  localparam s4 = 3'b100;39 40  reg [2:0] state;41  42  reg rd,rd_en;43  44  always @ (posedge sys_clk)45      begin46          if (!soft_rst_n)47              begin48                  rd <= 0;49              end50          else51              begin52                  if (local_rdreq && rd_en)53                      rd <= local_rdreq;54                  else55                      if (!rd_en)56                          rd <= 0;57                      else58                          rd <= rd;59              end60      end61  62      reg wr,wr_en;63  64  always @ (posedge sys_clk)65      begin66          if (!soft_rst_n)67              begin68                  wr <= 0;69              end70          else71              begin72                  if (local_wrreq && wr_en)73                      wr <= local_wrreq;74                  else75                      if (!wr_en)76                          wr <= 0;77                      else78                          wr <= wr;79              end80      end81  82  83  always @ (posedge sys_clk)84  begin85      if (!soft_rst_n)86          begin87              mux_sel <= `INIT;88              init_rst_n <= 0;89              ref_rst_n <= 0;90              wr_rst_n <= 0;91              rd_rst_n <= 0;92              time_rst_n <= 0;93              state <= s0;94 //               local_rdata <= 32'd0;95              local_ready <= 0;       96              rd_finish <= 0;  97              wr_finish <= 0;98 //               wr_data <= 32'd0;99              int_addr <= 25'd0;100             wr_en <= 1;101             rd_en <= 1;102             local_finish <= 0;103         end104     else105         case (state)106         s0 :  if (!init_done)107                     init_rst_n <= 1;108                 else  109                     begin110                         init_rst_n <= 0;111                         mux_sel <= `REF;112                         time_rst_n <= 1;113                         state <= s1;114                         local_ready <= 1;115                         wr_en <= 1;116                         rd_en <= 1;117                     end118                     119         s1 :  if ((ref_time < `ctREFR) && (!wr) && (!rd)) 120                     state <= s1;121                 else if (rd)    122                     begin123                         int_addr <= rd_ddr;124                         rd_rst_n <= 1;125                         mux_sel <= `READ;126                         local_ready <= 0;127                         rd_finish <= 0;128                         state <= s3;129                         rd_en <= 0;130                     end 131                 else if (wr)    132                     begin133                         int_addr <= wr_ddr;134//                           wr_data <= local_wdata;135                         wr_rst_n <= 1;136                         mux_sel <= `WRITE;137                         local_ready <= 0;138                         wr_finish <= 0;139                         state <= s4;140                         wr_en <= 0;141                     end                         142                 else if (ref_time >= `ctREFR)143                     begin144                         ref_rst_n <= 1;                                     145                         time_rst_n <= 0;    146                         mux_sel <= `REF;147                         state <= s2;148                         local_ready <= 0;   149                         local_finish <= 0;                      150                     end151         152         s2 :    if (!ref_done)153                     state <= s2;154                 else155                     begin156                         state <= s1;157                         time_rst_n <= 1;158                         ref_rst_n <= 0;159                         local_finish <= 1;160                         local_ready <= 1;   161                     end162         163         s3 :    if (!rd_done)164                     state <= s3;165                 else166                     begin167                         local_ready <= 1;168                         rd_finish <= 1;169                         rd_rst_n <= 0;170//                           local_rdata <= rd_data;171                         state <= s1;172                         rd_en <= 1;173                     end174         175         s4 :    if (!wr_done)176                     state <= s4;177                 else178                     begin179                         local_ready <= 1;180                         wr_finish <= 1;181                         wr_rst_n <= 0;182                         state <= s1;183                         wr_en <= 1;184                     end185         186         default : state <= s0;187         endcase188 end189 endmodule

图像实时显示模块的主要代码：

1 module lcd_driver2 (     3   //global clock4   input           clk,            //system clock5   input           rst_n,          //sync reset6   7   //lcd interface8   output          lcd_dclk,       //lcd pixel clock9   output          lcd_blank,      //lcd blank10  output          lcd_sync,       //lcd sync11  output          lcd_hs,         //lcd horizontal sync12  output          lcd_vs,         //lcd vertical sync13  output          lcd_en,         //lcd display enable14  output  [15:0]  lcd_rgb,        //lcd display data1516  //user interface17  output          lcd_request,    //lcd data request18  output  [10:0]  lcd_xpos,       //lcd horizontal coordinate19  output  [10:0]  lcd_ypos,       //lcd vertical coordinate20  input   [15:0]  lcd_data        //lcd data21);     22`include "lcd_para.v"  2324/*******************************************25      SYNC--BACK--DISP--FRONT26*******************************************/27//------------------------------------------28//h_sync counter & generator29 reg [10:0] hcnt; 30 always @ (posedge clk or negedge rst_n)31 begin32  if (!rst_n)33      hcnt <= 11'd0;34  else35      begin36        if(hcnt < `H_TOTAL - 1'b1)        //line over         37            hcnt <= hcnt + 1'b1;38        else39            hcnt <= 11'd0;40      end41 end 42 assign   lcd_hs = (hcnt <= `H_SYNC - 1'b1) ? 1'b0 : 1'b1;4344//------------------------------------------45//v_sync counter & generator46 reg [10:0] vcnt;47 always@(posedge clk or negedge rst_n)48 begin49  if (!rst_n)50      vcnt <= 11'b0;51  else if(hcnt == `H_TOTAL - 1'b1)        //line over52      begin53      if(vcnt < `V_TOTAL - 1'b1)      //frame over54          vcnt <= vcnt + 1'b1;55      else56          vcnt <= 11'd0;57      end58 end59 assign   lcd_vs = (vcnt <= `V_SYNC - 1'b1) ? 1'b0 : 1'b1;6061//------------------------------------------62//LCELL   LCELL(.in(clk),.out(lcd_dclk));63 assign   lcd_dclk = ~clk;64 assign   lcd_blank = lcd_hs & lcd_vs;        65 assign   lcd_sync = 1'b0;6667//-----------------------------------------68 assign   lcd_en      =   (hcnt >= `H_SYNC + `H_BACK  && hcnt < `H_SYNC + `H_BACK + `H_DISP) &&69                      (vcnt >= `V_SYNC + `V_BACK  && vcnt < `V_SYNC + `V_BACK + `V_DISP) 70                      ? 1'b1 : 1'b0;71 assign   lcd_rgb     =   lcd_en ? (lcd_data > 5) ? 16'd0 : 16'hffff : 16'd0;72////assign    lcd_rgb     =   lcd_en ? {lcd_data[10:6],lcd_data[10:5],lcd_data[10:6]} : 16'd0;73//assign  lcd_rgb     =   lcd_en ? {lcd_data[7:3],lcd_data[7:2],lcd_data[7:3]} : 16'd0;74//assign  lcd_rgb     =   lcd_en ? lcd_data : 16'd0;7576//------------------------------------------77//ahead x clock78 localparam   H_AHEAD = 2'd1;79 assign   lcd_request =   (hcnt >= `H_SYNC + `H_BACK - H_AHEAD && hcnt < `H_SYNC + `H_BACK + `H_DISP - H_AHEAD) &&80                      (vcnt >= `V_SYNC + `V_BACK && vcnt < `V_SYNC + `V_BACK + `V_DISP) 81                      ? 1'b1 : 1'b0;82//-----------------------------------------83//lcd xpos & ypos84 assign   lcd_xpos    =   lcd_request ? (hcnt - (`H_SYNC + `H_BACK - 1'b1)) : 11'd0;85 assign   lcd_ypos    =   lcd_request ? (vcnt - (`V_SYNC + `V_BACK - 1'b1)) : 11'd0;86 endmodule

本篇到此结束，基于FPGA的实时图像边缘检测系统设计介绍完毕，各位大侠，关注不迷路哦，有缘再见。