LCD字符图片显示——FPGA学习笔记11

一、字模显示原理

字模数据：将这个0/1矩阵按照屏幕扫描的顺序以字节的形式体现。

取模软件设计：

点阵数要按照实际情况填写

 二、实验任务

        本节的实验任务是通过开发板上的RGB TFT-LCD接口，在RGB LCD液晶屏的左上角位置从上到下依次显示图片以及汉字“你好，FPGA”。其中每个汉字的大小为32*32，图片的大小为770*306。

三、程序设计

1、lcd_display框架：

`timescale 1ns / 1psmodule lcd_display(
input               sys_clk     ,       
input               sys_rst_n   ,       input       [10:0]  pixel_xpos  ,       //像素点横坐标
input       [10:0]  pixel_ypos  ,       //像素点纵坐标
output  reg [23:0]  pixel_data          //像素点数据);localparam  PIC_X_START     = 11'd15;      //图片起始点横坐标
localparam  PIC_Y_START     = 11'd15;       //图片起始点纵坐标
localparam  PIC_WIDTH       = 11'd164;      //图片宽度
localparam  PIC_HEIGHT      = 11'd57;      //图片高度localparam  CHAR_X_START    = 11'd15;      //字符起始点横坐标
localparam  CHAR_Y_START    = 11'd75;       //字符起始点纵坐标
localparam  CHAR_WIDTH      = 11'd160;      //字符宽度
localparam  CHAR_HEIGHT     = 11'd32;       //字符高度localparam  BACK_COLOR      = 24'hE0FFFF;   //背景颜色  浅蓝色
localparam  CHAR_COLOR      = 24'hff0000;   //字体颜色，红色reg     [160:0] char[31:0]  ;       //二维寄存器
reg     [13:0]  rom_addr    ;       //ROM地址wire    [10:0]  x_cnt       ;
wire    [10:0]  y_cnt       ;
wire            rom_rd_en   ;
wire    [23:0]  rom_rd_data ;assign rom_rd_en = 1'b1;            //始终使能
assign x_cnt = pixel_xpos + 1'b1 - CHAR_X_START;
assign y_cnt = pixel_ypos - CHAR_Y_START;//给二维寄存器写入字符信息   你好，FPGA
always @(posedge sys_clk) beginchar[0 ] <= 160'h0000000000000000000000000000000000000000;char[1 ] <= 160'h0000000000000000000000000000000000000000;char[2 ] <= 160'h0000000000000000000000000040000001000000;char[3 ] <= 160'h0000000000000000000000000070600001C00000;char[4 ] <= 160'h0000000000000000000000000060E00001800020;char[5 ] <= 160'h00000000000000000000000000E0C0000181FFF0;char[6 ] <= 160'h7FFC7FF003C003800000000000C0C00001800070;char[7 ] <= 160'h181C18180C3003800000000000C18000010000C0;char[8 ] <= 160'h1804180C08100380000000000181801803080080;char[9 ] <= 160'h1802180618180380000000000103FFFC3FFC0100;char[10] <= 160'h18021806300804C0000000000303001803080600;char[11] <= 160'h18001806300804C0000000000386103003080600;char[12] <= 160'h18001806200004C00000000007840C2002180600;char[13] <= 160'h18101806600004C0000000000D8C084006180600;char[14] <= 160'h1810180660000C40000000000988080006180600;char[15] <= 160'h1830180C60000860000000001190080004180618;char[16] <= 160'h1FF018186000086000000000118188000417FFFC;char[17] <= 160'h18301FE06000086000000000218388800C300600;char[18] <= 160'h18101800607E182000000000018308400C300600;char[19] <= 160'h1810180060181FF0000000000183082008300600;char[20] <= 160'h1810180060181030070000000186083008600600;char[21] <= 160'h18001800201810300F800000018608180E600600;char[22] <= 160'h18001800301810300F800000018C081C01C00600;char[23] <= 160'h1800180030182018078000000188080C00F00600;char[24] <= 160'h1800180010182018018000000190080C00BC0600;char[25] <= 160'h1800180018182018030000000190080C018C0600;char[26] <= 160'h180018000C20601C0200000001A0080003040600;char[27] <= 160'h7E007E0007C0F83E040000000180080004000600;char[28] <= 160'h0000000000000000180000000180F8000800FC00;char[29] <= 160'h0000000000000000000000000180380030001C00;char[30] <= 160'h0000000000000000000000000100100000000800;char[31] <= 160'h0000000000000000000000000000000000000000;/*"D:\开发素材\FPGA文本\FPGA你好.BMP",0*/
end//为LCD不同区域显示绘制图片、字符和背景颜色
always @(posedge sys_clk or negedge sys_rst_n ) beginif (!sys_rst_n) beginpixel_data <= 24'h0;end else if((pixel_xpos >= PIC_X_START - 1'b1) && (pixel_xpos < PIC_X_START + PIC_WIDTH - 1'b1) && (pixel_ypos >= PIC_Y_START) && (pixel_ypos < PIC_Y_START + PIC_HEIGHT))beginpixel_data <= rom_rd_data;endelse if ((pixel_xpos >= CHAR_X_START - 1'b1) && (pixel_xpos < CHAR_X_START + CHAR_WIDTH - 1'b1) && (pixel_ypos >= CHAR_Y_START) && (pixel_ypos < CHAR_Y_START + CHAR_HEIGHT)) beginif (char[y_cnt][CHAR_WIDTH -1'b1 - x_cnt] == 1'b1) beginpixel_data <= CHAR_COLOR;end else beginpixel_data <= BACK_COLOR;endendelse beginpixel_data <= BACK_COLOR;end
end//根据当前扫描点的横纵坐标为ROM地址赋值
always @(posedge sys_clk or negedge sys_rst_n ) beginif (!sys_rst_n) beginrom_addr <= 14'd0;end //当位于图片显示区域的时候ROM地址进行累加else if((pixel_ypos >= PIC_Y_START) && (pixel_ypos < PIC_Y_START + PIC_HEIGHT) && (pixel_xpos >= PIC_X_START - 2'd2) && (pixel_xpos < PIC_X_START + PIC_WIDTH - 2'd2))beginrom_addr <= rom_addr + 1'b1;                                                   end//当横坐标位于图片最后一个像素点时，ROM地址清零else if (pixel_ypos >= PIC_Y_START + PIC_HEIGHT) beginrom_addr <= 18'd0;end else beginrom_addr <= rom_addr;end
endRGB_LCD u_RGB_LCD (.clka(sys_clk),    // input wire clka.ena(rom_rd_en),      // input wire ena.addra(rom_addr),  // input wire [13 : 0] addra.douta(rom_rd_data)  // output wire [23 : 0] douta);endmodule

其他部分均沿用上期博客LCD彩条显示——FPGA学习笔记10-CSDN博客的代码

文件结构如图所示：

2、ROM  IP核

3、仿真

字符显示：

图片显示：

四、下载验证

五、总结