基于verilog的LCD驅(qū)動(dòng)實(shí)時(shí)控制電路設(shè)計(jì)

1、 點(diǎn)陣字符型液晶顯示器驅(qū)動(dòng)控制電路設(shè)計(jì)實(shí)驗(yàn)?zāi)康模菏煜erilog狀態(tài)機(jī)的一般形式，使用狀態(tài)機(jī)控制LCD 1602顯示器。實(shí)驗(yàn)內(nèi)容： 設(shè)計(jì)LCD102顯示器控制器，實(shí)現(xiàn)在LCD屏上實(shí)時(shí)顯示ASCII字符。顯示地址、顯示ASCII碼分別由SW12-SW8和SW7-SW0設(shè)定。LCD1602的硬件特性及引腳功能 LCD1602顧名思義是一種02*16，即為兩行十六列的液晶顯示屏，液晶兩行，每行可以顯示16個(gè)字符，但是CGRAM及CGROM里面一共有160個(gè)字符，包括阿拉伯?dāng)?shù)字，英文字母大小寫(xiě)，常用符號(hào)及日文。每個(gè)字符對(duì)應(yīng)于一個(gè)ASCII碼值，在液晶顯示屏上顯示對(duì)應(yīng)的字符時(shí)候，只需要將對(duì)應(yīng)的ASCI

2、I碼寫(xiě)到DDRAM中就好，詳細(xì)的步驟會(huì)在下面細(xì)說(shuō)。液晶板上排列著5*8的字符點(diǎn)陣，8行，每行5個(gè)點(diǎn)位，高電平1就是該點(diǎn)顯示，低電平0就是該點(diǎn)不顯示。當(dāng)然有的模塊是不帶背光的，這時(shí)候15 和16引腳是沒(méi)有意義的程序代碼源：module lcd_1602(clk50m,lcd_en,key,sw_data,address,rst,lcd_rw,lcd_rs,lcd_data,lcd_on,lcd_blon);input rst;input key;input clk50m;input 4:0address; /顯示地址輸入input 7:0sw_data; /顯示數(shù)據(jù)輸入output lcd_en

3、; /連在clk4hz的時(shí)鐘信號(hào)上output lcd_rw;output lcd_rs;output lcd_on;output lcd_blon; / (背光) 懸空，相當(dāng)于低電平output reg7:0lcd_data;reg 7:0buf_data;reg 7:0buf_addr;reg lcd_rw,lcd_rs, clk4hz,lcd_on,lcd_blon;reg7:0 state; reg23:0cnt;reg load;parameter OP =8'b0000_0001;parameter CLEAR =8'b0000_0010; /清屏parameter

4、 SETFUNCTION =8'b0000_0100; /設(shè)置 CGRAMparameter SWITCHMODE=8'b0000_1000; /工作方式設(shè)置1:8/ 1:4位數(shù)據(jù)接口； 兩行/一行顯示方式； 5x10/5x7點(diǎn)陣parameter SETMODE =8'b0001_0000; / 顯示狀態(tài)設(shè)置，顯示開(kāi)/關(guān)； 光標(biāo)開(kāi)/關(guān)；閃爍開(kāi)/關(guān)parameter JUDGE =8'b0010_0000; /輸入方式設(shè)置， 讀寫(xiě)數(shù)據(jù)后RAM地址增減1，畫(huà)面不動(dòng)parameter JUDGE_new =8'b0011_0000;parameter SET

5、CGRAM =8'b0100_0000; /寫(xiě)RAMparameter WRITERAM =8'b1000_0000;parameter CUR_INC =1'b1; /功能參數(shù)設(shè)定parameter CUR_NOSHIFT =1'b0;parameter OPEN_DISPLAY =1'b1;parameter OPEN_CUR =1'b0;parameter BLANK_CUR =1'b0;parameter DATAWITH8 =1'b1;parameter DATAWIHT4 =1'b0;parameter TWO

6、LINE =1'b1 ;parameter ONELINE =1'b0;parameter FONT5x10 =1'b1;parameter FONT5x7 =1'b0;always(posedge clk50m ) begin if (cnt=23'd125000) begin cnt<=0; clk4hz<=clk4hz; end else cnt<=cnt+1'b1; end assign lcd_en=clk4hz; always(posedge clk4hz ) /clk4hz 接 lcd_en 使能引腳 begin

7、if(rst) begin state<=CLEAR; lcd_on<=0; lcd_blon<=0; end else begin state<=CLEAR; lcd_on<=1;lcd_blon<=1; /buf_addr<=3'b100,address; /buf_data7:0<=sw_data; case(state) CLEAR: begin lcd_rs<=0; lcd_rw<=0; lcd_data<=8'b00000001; state<=SETFUNCTION; end SETFUNCT

8、ION:begin / 00_0011_1000 lcd_rs<=0; lcd_rw<=0; lcd_data7:5<=3'b001; lcd_data4<=DATAWITH8; lcd_data3<=TWOLINE; lcd_data2<=FONT5x7; lcd_data1:0<=2'b00; state<=SETMODE; end SETMODE:begin /該狀態(tài)可有可無(wú)， 決定 讀寫(xiě)數(shù)據(jù)后光標(biāo)移動(dòng)方向 lcd_rs<=0; lcd_rw<=0; lcd_data7:2<=6'b000001;

9、/ 00_0000_0110 lcd_data1<=CUR_INC; lcd_data0<=CUR_NOSHIFT; state<=SWITCHMODE; end SWITCHMODE:begin lcd_rs<=0; lcd_rw<=0; / 00_0000_1100 lcd_data7:3<=5'b00001; lcd_data2<=OPEN_DISPLAY; lcd_data1<=OPEN_CUR; lcd_data0<=BLANK_CUR; state<=JUDGE; end JUDGE:begin lcd_rs<

10、;=0; lcd_rw<=1;lcd_data<=8'b10000000; /load<=1; load<=key; if(key=load) /利用非阻塞阻塞實(shí)現(xiàn)使能控制 /在key被按一直下的時(shí)候撥動(dòng)開(kāi)關(guān) /不會(huì)改變屏幕的顯示 state<=JUDGE; /且松開(kāi)key后，以最后的開(kāi)關(guān)狀態(tài)為最終顯示 else begin state<=SETCGRAM;if(address4) beginbuf_addr<=4'b1100,address3:0; /顯示第二行數(shù)據(jù) buf_data<=sw_data; endelsebeginbuf_addr<=3'b100,address; /顯示第一行數(shù)據(jù)buf_data<=sw_data;end end end SETCGRAM:begin lcd_rs<=0; lcd_rw=0; lcd_data<=buf_addr; state<= WRITERAM; end