Verilog实现VGA显示控制器

Verilog实现VGA显示控制器

 

    具体原理就不详细讲了，这里给出完整的代码以及Nexys3开发板的引脚文件。

 

    最终实现的效果是：

        以 640*480 的分辨率在显示器屏幕显示一个矩形方块,方块在屏幕中以 45 度的角度、60 像素/秒的速度移动,到达屏幕边沿的时候反弹。

 

 
Verilog代码  收藏代码

    // 设计文件：vga_controller.v  
    `timescale 1ns / 1ps  
      
    module vga_controller(  
        input clk,  
        input rst,  
        output reg [2:0] r,  
        output reg [2:0] g,  
        output reg [1:0] b,  
        output hs,  
        output vs  
        );  
      
        parameter UP_BOUND = 31;  
        parameter DOWN_BOUND = 510;  
        parameter LEFT_BOUND = 144;  
        parameter RIGHT_BOUND = 783;  
          
        reg h_speed, v_speed;  
        reg [9:0] up_pos, down_pos, left_pos, right_pos;  
      
        wire pclk;  
        reg [1:0] count;  
        reg [9:0] hcount, vcount;  
          
        // 获得像素时钟25MHz  
        assign pclk = count[1];  
        always @ (posedge clk)  
        begin  
            if (rst)  
                count <= 0;  
            else  
                count <= count+1;  
        end  
          
        // 列计数与行同步  
        assign hs = (hcount < 96) ? 0 : 1;  
        always @ (posedge pclk or posedge rst)  
        begin  
            if (rst)  
                hcount <= 0;  
            else if (hcount == 799)  
                hcount <= 0;  
            else  
                hcount <= hcount+1;  
        end  
          
        // 行计数与场同步  
        assign vs = (vcount < 2) ? 0 : 1;  
        always @ (posedge pclk or posedge rst)  
        begin  
            if (rst)  
                vcount <= 0;  
            else if (hcount == 799) begin  
                if (vcount == 520)  
                    vcount <= 0;  
                else  
                    vcount <= vcount+1;  
            end  
            else  
                vcount <= vcount;  
        end  
          
        // 显示方块  
        always @ (posedge pclk or posedge rst)  
        begin  
            if (rst) begin  
                r <= 0;  
                g <= 0;  
                b <= 0;  
            end  
            else begin  
                if (vcount>=up_pos && vcount<=down_pos  
                        && hcount>=left_pos && hcount<=right_pos) begin  
                    r <= 3'b000;  
                    g <= 3'b111;  
                    b <= 2'b00;  
                end  
                else begin  
                    r <= 3'b000;  
                    g <= 3'b000;  
                    b <= 2'b00;  
                end  
            end  
        end  
          
        // 每一帧动画之后根据方块当前位置调整速度  
        always @ (negedge vs or posedge rst)  
        begin  
            if (rst) begin  
                h_speed <= 1;  
                v_speed <= 0;  
            end  
            else begin  
                if (up_pos == UP_BOUND)  
                    v_speed <= 1;  
                else if (down_pos == DOWN_BOUND)  
                    v_speed <= 0;  
                else  
                    v_speed <= v_speed;  
                  
                if (left_pos == LEFT_BOUND)  
                    h_speed <= 1;  
                else if (right_pos == RIGHT_BOUND)  
                    h_speed <= 0;  
                else  
                    h_speed <= h_speed;  
            end  
        end  
          
        // 每一帧动画之后根据速度值更新方块的位置  
        always @ (posedge vs or posedge rst)  
        begin  
            if (rst) begin  
                up_pos <= 391;  
                down_pos <= 510;  
                left_pos <= 384;  
                right_pos <= 543;  
            end  
            else begin  
                if (v_speed) begin  
                    up_pos <= up_pos+1;  
                    down_pos <= down_pos+1;  
                end  
                else begin  
                    up_pos <= up_pos-1;  
                    down_pos <= down_pos-1;  
                end  
                  
                if (h_speed) begin  
                    left_pos <= left_pos+1;  
                    right_pos <= right_pos+1;  
                end  
                else begin  
                    left_pos <= left_pos-1;  
                    right_pos <= right_pos-1;  
                end  
            end  
        end  
      
    endmodule  

 

 
Verilog代码  收藏代码

    // Nexys3开发板引脚文件  
    NET "clk" LOC = "V10";  
    NET "rst" LOC = "C9";  
      
    NET "r[0]" LOC = "U7";  
    NET "r[1]" LOC = "V7";  
    NET "r[2]" LOC = "N7";  
    NET "g[0]" LOC = "P8";  
    NET "g[1]" LOC = "T6";  
    NET "g[2]" LOC = "V6";  
    NET "b[0]" LOC = "R7";  
    NET "b[1]" LOC = "T7";  
      
    NET "hs" LOC = "N6";  
    NET "vs" LOC = "P7";