lcd.v

lcd1602的源程序Vrilog HDL语言编写

`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company: 
// Engineer: 
// 
// Create Date:    20:48:44 03/10/2009 
// Design Name: 
// Module Name:    lcd 
// Project Name: 
// Target Devices: 
// Tool versions: 
// Description: 
//
// Dependencies: 
//
// Revision: 
// Revision 0.01 - File Created
// Additional Comments: 
//
//////////////////////////////////////////////////////////////////////////////////
module lcd(clk,lcd_e,lcd_rs,lcd_rw,lcd_4,lcd_5,lcd_6,lcd_7);
                    parameter       n = 27; 
                    parameter       k = 17; 
                    input           clk;    // 输入时钟
                    reg     [n-1:0] count=0; 
                    reg             lcd_busy=1;  // 忙判断标志位
                    reg             lcd_stb; 
                    reg       [5:0] lcd_code; 
                    reg       [6:0] lcd_stuff;
                    reg     [0:127]  cod="LIYANJUNliumeila";						  
                    output reg      lcd_rs; 
                    output reg      lcd_rw; 
                    output reg      lcd_7; 
                    output reg      lcd_6; 
                    output reg      lcd_5; 
                    output reg      lcd_4; 
                    output reg      lcd_e; 

  always @ (posedge clk) 
  begin 
    count <= count + 1; 
    case (count[k+7:k+2]) 
       0: lcd_code <= 6'b000010;    // function set 
       1: lcd_code <= 6'b000010; 
       2: lcd_code <= 6'b001100; 
       3: lcd_code <= 6'b000000;    // display on/off control 
       4: lcd_code <= 6'b001100; 
       5: lcd_code <= 6'b000000;    // display clear 
       6: lcd_code <= 6'b000001; 
       7: lcd_code <= 6'b000000;    // entry mode set 
       8: lcd_code <= 6'b000110; 
       9: lcd_code <= {2'h2,cod[0:3]};        //显示code中的内容8*16=128位
      10: lcd_code <= {2'h2,cod[4:7]}; 
      11: lcd_code <= {2'h2,cod[8:11]};        
      12: lcd_code <= {2'h2,cod[12:15]}; 
      13: lcd_code <= {2'h2,cod[16:19]};        
      14: lcd_code <= {2'h2,cod[20:23]}; 
      15: lcd_code <= {2'h2,cod[24:27]};        
      16: lcd_code <= {2'h2,cod[28:31]}; 
      17: lcd_code <= {2'h2,cod[32:35]};       
      18: lcd_code <= {2'h2,cod[36:39]}; 
      19: lcd_code <= {2'h2,cod[40:43]};        
      20: lcd_code <= {2'h2,cod[44:47]}; 
      21: lcd_code <= {2'h2,cod[48:51]};        
      22: lcd_code <= {2'h2,cod[52:55]}; 
      23: lcd_code <= {2'h2,cod[56:59]};        
      24: lcd_code <= {2'h2,cod[60:63]}; 
      25: lcd_code <= {2'h2,cod[64:67]};        
      26: lcd_code <= {2'h2,cod[68:71]}; 
      27: lcd_code <= {2'h2,cod[72:75]};       
      28: lcd_code <= {2'h2,cod[76:79]}; 
      29: lcd_code <= {2'h2,cod[80:83]};        
      30: lcd_code <= {2'h2,cod[84:87]}; 
      31: lcd_code <= {2'h2,cod[88:91]};        
      32: lcd_code <= {2'h2,cod[92:95]}; 
		33: lcd_code <= {2'h2,cod[96:99]}; 
		34: lcd_code <= {2'h2,cod[100:103]}; 
		35: lcd_code <= {2'h2,cod[104:107]}; 
		36: lcd_code <= {2'h2,cod[108:111]}; 
		37: lcd_code <= {2'h2,cod[112:115]}; 
		38: lcd_code <= {2'h2,cod[116:119]}; 
		39: lcd_code <= {2'h2,cod[120:123]}; 
		40: lcd_code <= {2'h2,cod[124:127]}; 
      default: lcd_code <= 6'b010000; 
    endcase 
    if (lcd_rw) 
      lcd_busy <= 0; 
      lcd_stb <= ^count[k+1:k+0] & ~lcd_rw & lcd_busy;  // clkrate / 2^(k+2) 
      lcd_stuff <= {lcd_stb,lcd_code}; 
      {lcd_e,lcd_rs,lcd_rw,lcd_7,lcd_6,lcd_5,lcd_4} <= lcd_stuff; 
  end 


endmodule