LCD1602驱动 (amobbs.com 阿莫电子技术论坛) -

tear086 发表于 2010-2-1 22:08:42

LCD1602驱动

新近写的，水平有限，欢迎拍砖。

实验程序：
---------------------------------------------------
module lcd1602_drive(
input          clk,
input          rst_n,
// LCD1602 Interface
output reg lcd_data,
output       lcd_e,
output reg    lcd_rs,
output       lcd_rw
);

// +++++++++++++++++++++++++++++++++++++
// 分频模块开始
// +++++++++++++++++++++++++++++++++++++
parameter CLK_DIV = 10_0000;          // 分频参数
reg cnt;                      // 分频计数子
reg lcd_clk;                         // 500Hz

// 将50MHz板载时钟分频至500Hz
// 注：计数分频，非等占空比
always @(posedge clk, negedge rst_n)
begin
if(!rst_n)
begin cnt <= 1'b0; lcd_clk <= 0; end
else
begin
if(cnt <= CLK_DIV)
begin cnt <= cnt + 1'b1; lcd_clk <= 1; end
else
begin cnt <= 1'b0;    lcd_clk <= 0; end
end
end
// -------------------------------------
// 分频模块结束
// -------------------------------------

// +++++++++++++++++++++++++++++++++++++
// LCD1602驱动模块开始
// +++++++++++++++++++++++++++++++++++++
/*
* 格雷码编码
* 状态数：初始化5个；换行1个；数据32个；空闲1个；共39个。
*/
// 初始化
parameter INIT_0= 8'h00;
parameter INIT_1= 8'h01;
parameter INIT_2= 8'h03;
parameter INIT_3= 8'h02;
parameter INIT_4= 8'h06;
// 显示第一行
parameter ROW1_0= 8'h07;
parameter ROW1_1= 8'h05;
parameter ROW1_2= 8'h04;
parameter ROW1_3= 8'h0C;
parameter ROW1_4= 8'h0D;
parameter ROW1_5= 8'h0F;
parameter ROW1_6= 8'h0E;
parameter ROW1_7= 8'h0A;
parameter ROW1_8= 8'h0B;
parameter ROW1_9= 8'h09;
parameter ROW1_A= 8'h08;
parameter ROW1_B= 8'h18;
parameter ROW1_C= 8'h19;
parameter ROW1_D= 8'h1B;
parameter ROW1_E= 8'h1A;
parameter ROW1_F= 8'h1E;
// 换行
parameter CH_ROW= 8'h1F;
// 显示第二行
parameter ROW2_0= 8'h1D;
parameter ROW2_1= 8'h1C;
parameter ROW2_2= 8'h14;
parameter ROW2_3= 8'h15;
parameter ROW2_4= 8'h17;
parameter ROW2_5= 8'h16;
parameter ROW2_6= 8'h12;
parameter ROW2_7= 8'h13;
parameter ROW2_8= 8'h11;
parameter ROW2_9= 8'h10;
parameter ROW2_A= 8'h30;
parameter ROW2_B= 8'h31;
parameter ROW2_C= 8'h33;
parameter ROW2_D= 8'h32;
parameter ROW2_E= 8'h36;
parameter ROW2_F= 8'h37;
// 空闲
parameter IDLE = 8'h35;

reg current_state, next_state; // 现态、次态

// FSM: always1
always @ (posedge lcd_clk, negedge rst_n)
if(!rst_n)current_state <= INIT_0;
else    current_state <= next_state;

// FSM: always2
always
begin
case(current_state)
// 初始化
INIT_0: next_state = INIT_1;
INIT_1: next_state = INIT_2;
INIT_2: next_state = INIT_3;
INIT_3: next_state = INIT_4;
INIT_4: next_state = ROW1_0;
// 显示第一行
ROW1_0: next_state = ROW1_1;
ROW1_1: next_state = ROW1_2;
ROW1_2: next_state = ROW1_3;
ROW1_3: next_state = ROW1_4;
ROW1_4: next_state = ROW1_5;
ROW1_5: next_state = ROW1_6;
ROW1_6: next_state = ROW1_7;
ROW1_7: next_state = ROW1_8;
ROW1_8: next_state = ROW1_9;
ROW1_9: next_state = ROW1_A;
ROW1_A: next_state = ROW1_B;
ROW1_B: next_state = ROW1_C;
ROW1_C: next_state = ROW1_D;
ROW1_D: next_state = ROW1_E;
ROW1_E: next_state = ROW1_F;
ROW1_F: next_state = CH_ROW;
// 换行
CH_ROW: next_state = ROW2_0;
// 显示第二行
ROW2_0: next_state = ROW2_1;
ROW2_1: next_state = ROW2_2;
ROW2_2: next_state = ROW2_3;
ROW2_3: next_state = ROW2_4;
ROW2_4: next_state = ROW2_5;
ROW2_5: next_state = ROW2_6;
ROW2_6: next_state = ROW2_7;
ROW2_7: next_state = ROW2_8;
ROW2_8: next_state = ROW2_9;
ROW2_9: next_state = ROW2_A;
ROW2_A: next_state = ROW2_B;
ROW2_B: next_state = ROW2_C;
ROW2_C: next_state = ROW2_D;
ROW2_D: next_state = ROW2_E;
ROW2_E: next_state = ROW2_F;
ROW2_F: next_state = IDLE;
// 空闲
IDLE : next_state = IDLE;
default : next_state = INIT_0;
endcase
end

// FSM: always3
always @ (posedge lcd_clk, negedge rst_n)
begin
if(!rst_n)
begin lcd_rs <= 0; lcd_data <= 8'h00; end
else
begin
case(current_state)
   INIT_0, CH_ROW, IDLE: lcd_rs <= 0;// 开始写指令
   ROW1_0, ROW2_0    : lcd_rs <= 1;// 开始写数据
endcase

case(current_state)
   // 写指令，初始化
   INIT_0: lcd_data <= 8'h38;
   INIT_1: lcd_data <= 8'h0C;
   INIT_2: lcd_data <= 8'h01;
   INIT_3: lcd_data <= 8'h06;
   INIT_4: lcd_data <= 8'H80;
   // 写数据，显示第一行
   ROW1_0: lcd_data <= "a";
   ROW1_1: lcd_data <= "b";
   ROW1_2: lcd_data <= "c";
   ROW1_3: lcd_data <= "d";
   ROW1_4: lcd_data <= "e";
   ROW1_5: lcd_data <= "f";
   ROW1_6: lcd_data <= "g";
   ROW1_7: lcd_data <= "h";
   ROW1_8: lcd_data <= "i";
   ROW1_9: lcd_data <= "j";
   ROW1_A: lcd_data <= "k";
   ROW1_B: lcd_data <= "l";
   ROW1_C: lcd_data <= "m";
   ROW1_D: lcd_data <= "n";
   ROW1_E: lcd_data <= "o";
   ROW1_F: lcd_data <= "p";
   // 写指令，换行
   CH_ROW: lcd_data <= 8'hC0;
   // 写数据，显示第二行
   ROW2_0: lcd_data <= "A";
   ROW2_1: lcd_data <= "B";
   ROW2_2: lcd_data <= "C";
   ROW2_3: lcd_data <= "D";
   ROW2_4: lcd_data <= "E";
   ROW2_5: lcd_data <= "F";
   ROW2_6: lcd_data <= "G";
   ROW2_7: lcd_data <= "H";
   ROW2_8: lcd_data <= "I";
   ROW2_9: lcd_data <= "J";
   ROW2_A: lcd_data <= "K";
   ROW2_B: lcd_data <= "L";
   ROW2_C: lcd_data <= "M";
   ROW2_D: lcd_data <= "N";
   ROW2_E: lcd_data <= "O";
   ROW2_F: lcd_data <= "P";
   // 写指令，空闲
   IDLE : lcd_data <= 8'h00;
endcase
end
end

// 在时钟高电平有效，低电平失效
// 数据方可被锁存
assign lcd_e= lcd_clk;
assign lcd_rw = 1'b0;                // 只写

// -------------------------------------
// LCD1602驱动模块结束
// -------------------------------------

endmodule
---------------------------------------------------

实验现象：
http://cache.amobbs.com/bbs_upload782111/files_25/ourdev_531559.png
(原文件名:抓图-1.png)

Quartus II 综合报告：
http://cache.amobbs.com/bbs_upload782111/files_25/ourdev_531565.png
(原文件名:抓图-2.png)

tear086 发表于 2010-2-20 00:15:30

改进版测试文件

module lcd1602_test(
input    CLOCK_50,             // 板载时钟50MHz
input    Q_KEY,                // 板载按键RST
// LCD1602 Interface
output LCD1602_DATA,          // LCD1602数据总线
output    LCD1602_E,             // LCD1602使能
output    LCD1602_RS,          // LCD1602指令数据选择
output    LCD1602_RW             // LCD1602读写选择
);

// 0 ~ (8*16-1) = 128
// 16bits          -> 0123456789ABCDEF <-
wire row1_val = "A Lcd Disp Test ";
wire row2_val = "Amy-studio Pub";

// 例化LCD1602驱动
lcd1602_drive u0(
.clk(CLOCK_50),
.rst_n(Q_KEY),
// LCD1602 Input Value
.row1_val(row1_val),
.row2_val(row2_val),
// LCD1602 Interface
.lcd_data(LCD1602_DATA),
.lcd_e(LCD1602_E),
.lcd_rs(LCD1602_RS),
.lcd_rw(LCD1602_RW)
);

endmodule

完整代码（不晓得什么意思，ourdev一次能贴的代码太短）点击此处下载 ourdev_534318.zip(文件大小:125K) (原文件名:_10_lcd1602_test.zip)

vermon 发表于 2010-2-20 00:27:24

好帖记号！

lmldai 发表于 2010-3-10 20:50:34

学习了

anlimql 发表于 2010-3-11 22:25:12

好贴

amy-studio 发表于 2010-3-13 11:59:41

上图

http://cache.amobbs.com/bbs_upload782111/files_27/ourdev_538135.JPG
(原文件名:lcd1602液晶显示.JPG)

http://cache.amobbs.com/bbs_upload782111/files_27/ourdev_538136.JPG
(原文件名:lcd1602数字钟.JPG)

ruguo 发表于 2010-4-10 21:38:04

为什么我烧进去lcd1602上面什么都没有？

wuyongqing1960 发表于 2010-4-11 09:17:49

好贴，mark

vermon 发表于 2010-4-11 09:20:59

这个要记好非常好

ber619 发表于 2010-4-21 15:07:29

以为是HAL层驱动~~

pebble 发表于 2010-6-22 11:49:15

多谢lz的程序，我的一开始频率设的太高，总是不稳定，后来把频率降下来就好了

hbchf 发表于 2010-11-18 19:25:41

mark

tt88050643 发表于 2010-11-28 15:57:21

mark

AG17 发表于 2010-12-1 00:21:16

mark

suxilong 发表于 2010-12-1 09:29:54

txt文档中的：//在Quartus II中，使用Assignments-Import Assignment，导入该txt文件。

这个有什么作用？是不是输入管脚!!!!

suxilong 发表于 2010-12-1 17:16:36

// 将50MHz板载时钟分频至500Hz
// 注：计数分频，非等占空比
always @(posedge clk, negedge rst_n)
begin
if(!rst_n)
begin cnt <= 1'b0; lcd_clk <= 0; end
else
begin
if(cnt <= CLK_DIV)
begin cnt <= cnt + 1'b1; lcd_clk <= 1; end
else
begin cnt <= 1'b0; lcd_clk <= 0; end
end
这一段分频到时有什么用》？？？？？

尤其是这句话！！！！assign lcd_e= lcd_clk;

lb693294195 发表于 2011-11-17 18:01:56

回复【15楼】suxilong 小苏
-----------------------------------------------------------------------

高电平锁存，下降沿有效

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LCD1602驱动