lcd_1602驱动模板.docx

/模块功能说明 ：本模块为LCD_1602液晶屏的简单驱动模块，/实现的功能为 : 第一行显示字符Welcom you come ，/第二行显示字符Fpga learn，当第一行打印完以后开始/打印第二行，打印结束后，马上开始整体向左进行移位显示,/实现滚屏效果 /本模块已通过综合验证，并已经在开发板上调试通过/作者： 王建飞/*/模块端口定义module lcd(clk,rst,r_s,r_w,e,d);/*/端口类型说明input clk;input rst;output r_s;output r_w;output e;output 7:0 d;reg r_s;reg r_w;reg e;reg 3:0 cnt1; /字符打印计数器reg 8:0 state; /状态机主状态reg 7:0 d;reg 23:0cnt; /分频计数器reg 16*8-1:0 final_data1; /第一行显示数据寄存器reg 10*8-1:0 final_data2; /第二行显示数据寄存器/*/状态机参数定义parameterIDLE = 9b000000000;parameterSETFUNCTION_6 =9b000000001;parameterSWITCHMODE_4 =9b000000010;parameterCLEAR_1 = 9b000000100;parameterSETMODE_3 = 9b000001000;parameterSETDDRAM_8 = 9b000010000;parameterWRITERAM_1 = 9b000100000;parameterSETDDRAM_8_2 = 9b001000000;parameter WRITERAM_2 = 9b010000000;parameterSHIFT_5 = 9b100000000;/*/系统时钟分频always (posedge clk) if(!rst) begin cnt = 0;e = 0; endelse begincnt = cnt+1;e = cnt23;end/*/always (posedge e)if(!rst) /系统复位begin r_s = 0; r_w = 0; d = 0; end/*/LCD指令表示elsebegincase(state)/*空闲状态*/IDLE : begin state = SETFUNCTION_6; final_data1 = Welcom you come ; final_data2 = Fpga learn; end/*置功能*/SETFUNCTION_6 : beginr_s = 0;r_w = 0;d = 8b00111000; state = SWITCHMODE_4;end/*显示开关控制*/SWITCHMODE_4 : beginr_s = 0; r_w = 0; d = 8b00001100;state = CLEAR_1; end/*清屏*/CLEAR_1 : beginr_s = 0; r_w = 0;d = 8b00000001;state = SETMODE_3; end/*置输入模式*/SETMODE_3 : beginr_s = 0;r_w = 0;d = 8b00000110;state = SETDDRAM_8;end/*置第一行地址*/SETDDRAM_8 : beginr_s = 0;r_w = 0;d = 8b10000000;state = WRITERAM_1;end/*置第一行数据*/WRITERAM_1 : beginr_s = 1;r_w = 0;if(cnt1=15) begin state = SETDDRAM_8_2;cnt1 = 0;end d = final_data1127:120; / final_data=final_data8; （这种循环移位方式也是可以实现的，但是不支持重复打印，否则会出现数据错误） final_data1 = final_data1119:0,final_data1127:120; cnt1 = cnt1+1; end/*置第二行地址*/SETDDRAM_8_2 : beginr_s = 0;r_w = 0;d = 8b11000100;state = WRITERAM_2;end/*置第二行数据*/WRITERAM_2 : beginr_s = 1;r_w = 0;final_data2 = final_data271:0,final_data279:72;d = final_data279:72;cnt1 = cnt1+1;if(cnt1=9)begin cnt1 = 0; state = SHIFT_5;endend/*移位指令（左移）*/SHIFT_5 : beginr_s = 0;r