FPGA串行控制LCD12864
library ieee;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_unsigned.all;
use work.lcdchar.all;
entity display12864 is --LCD12864 display
generic( fclk : integer :=50000000);
port(
n_rst : in std_logic;
clk_in : in std_logic;
en : in std_logic;
SID : out std_logic;
SCLK : out std_logic
);
end display12864;
architecture rtl of display12864 is
constant div_num : integer :=fclk/500000;
--attention : '\' and '"' can't be displayed.
constant line1_str : string:=" test1 ";
constant line2_str : string:=" 2 ";
constant line3_str : string:=" 3 ";
constant line4_str : string:=" 4 ";
signal clk_500KHz : std_logic;
signal LCD_cnt : integer range 0 to 71;
signal LCD_Data : std_logic_vector(7 downto 0);
signal rs,LCD_cnt_en: std_logic;
signal clr : std_logic;
signal bit_cnt : integer range 0 to 25;
signal delay_over : std_logic;
constant delay_10ms : integer := 500000/100;--delay 10 ms
constant delay_1ms : integer := 500000/1000;--delay 1 ms
begin
--frequency division
process(clk_in,n_rst)
variable div_cnt : integer range 0 to div_num-1 ;
begin
if(n_rst='0')then
div_cnt:=0;
elsif(clk_in'event and clk_in='1') then
if(en='1')then
if(div_cnt>=div_num-1) then
div_cnt:=0;
else
if (div_cnt < div_num/2) then
clk_500KHz<='1';
else
clk_500KHz<='0';
end if;
div_cnt:=div_cnt + 1;
end if;
end if;
end if;
end process;
process(clk_500KHz,n_rst)
begin
if(n_rst='0')then
LCD_cnt<=0;
rs<='0';
LCD_Data<=x"00";
elsif(clk_500KHz'event and clk_500KHz='1')then
if(en='1')then
if(LCD_cnt>=71)then
LCD_cnt<=4;
elsif(delay_over='1')then
LCD_cnt<=LCD_cnt+1;
else
LCD_cnt<=LCD_cnt;
end if;
case LCD_cnt is
when 0 => rs<='0';LCD_Data<=x"30";
when 1 => rs<='0';LCD_Data<=x"01";
when 2 => rs<='0';LCD_Data<=x"06";
when 3 => rs<='0';LCD_Data<=x"0c";
when 4 => rs<='0';LCD_Data<=x"80"; --first line
when 5 => rs<='1';LCD_Data<=str2vector(line1_str,1);
when 6 => rs<='1';LCD_Data<=str2vector(line1_str,2);
when 7 => rs<='1';LCD_Data<=str2vector(line1_str,3);
when 8 => rs<='1';LCD_Data<=str2vector(line1_str,4);
when 9 => rs<='1';LCD_Data<=str2vector(line1_str,5);
when 10 => rs<='1';LCD_Data<=str2vector(line1_str,6);
when 11 => rs<='1';LCD_Data<=str2vector(line1_str,7);
when 12 => rs<='1';LCD_Data<=str2vector(line1_str,8);
when 13 => rs<='1';LCD_Data<=str2vector(line1_str,9);
when 14 => rs<='1';LCD_Data<=str2vector(line1_str,10);
when 15 => rs<='1';LCD_Data<=str2vector(line1_str,11);
when 16 => rs<='1';LCD_Data<=str2vector(line1_str,12);
when 17 => rs<='1';LCD_Data<=str2vector(line1_str,13);
when 18 => rs<='1';LCD_Data<=str2vector(line1_str,14);
when 19 => rs<='1';LCD_Data<=str2vector(line1_str,15);
when 20 => rs<='1';LCD_Data<=str2vector(line1_str,16);
when 21 => rs<='0';LCD_Data<=(x"90"); --second line
when 22 => rs<='1';LCD_Data<=str2vector(line2_str,1);
when 23 => rs<='1';LCD_Data<=str2vector(line2_str,2);
when 24 => rs<='1';LCD_Data<=str2vector(line2_str,3);
when 25 => rs<='1';LCD_Data<=str2vector(line2_str,4);
when 26 => rs<='1';LCD_Data<=str2vector(line2_str,5);
when 27 => rs<='1';LCD_Data<=str2vector(line2_str,6);
when 28 => rs<='1';LCD_Data<=str2vector(line2_str,7);
when 29 => rs<='1';LCD_Data<=str2vector(line2_str,8);
when 30 => rs<='1';LCD_Data<=str2vector(line2_str,9);
when 31 => rs<='1';LCD_Data<=str2vector(line2_str,10);
when 32 => rs<='1';LCD_Data<=str2vector(line2_str,11);
when 33 => rs<='1';LCD_Data<=str2vector(line2_str,12);
when 34 => rs<='1';LCD_Data<=str2vector(line2_str,13);
when 35 => rs<='1';LCD_Data<=str2vector(line2_str,14);
when 36 => rs<='1';LCD_Data<=str2vector(line2_str,15);
when 37 => rs<='1';LCD_Data<=str2vector(line2_str,16);
when 38 => rs<='0';LCD_Data<=(x"88"); --third line
when 39 => rs<='1';LCD_Data<=str2vector(line3_str,1);
when 40 => rs<='1';LCD_Data<=str2vector(line3_str,2);
when 41 => rs<='1';LCD_Data<=str2vector(line3_str,3);
when 42 => rs<='1';LCD_Data<=str2vector(line3_str,4);
when 43 => rs<='1';LCD_Data<=str2vector(line3_str,5);
when 44 => rs<='1';LCD_Data<=str2vector(line3_str,6);
when 45 => rs<='1';LCD_Data<=str2vector(line3_str,7);
when 46 => rs<='1';LCD_Data<=str2vector(line3_str,8);
when 47 => rs<='1';LCD_Data<=str2vector(line3_str,9);
when 48 => rs<='1';LCD_Data<=str2vector(line3_str,10);
when 49 => rs<='1';LCD_Data<=str2vector(line3_str,11);
when 50 => rs<='1';LCD_Data<=str2vector(line3_str,12);
when 51 => rs<='1';LCD_Data<=str2vector(line3_str,13);
when 52 => rs<='1';LCD_Data<=str2vector(line3_str,14);
when 53 => rs<='1';LCD_Data<=str2vector(line3_str,15);
when 54 => rs<='1';LCD_Data<=str2vector(line3_str,16);
when 55 => rs<='0';LCD_Data<=(x"98"); --forth line
when 56 => rs<='1';LCD_Data<=str2vector(line4_str,1);
when 57 => rs<='1';LCD_Data<=str2vector(line4_str,2);
when 58 => rs<='1';LCD_Data<=str2vector(line4_str,3);
when 59 => rs<='1';LCD_Data<=str2vector(line4_str,4);
when 60 => rs<='1';LCD_Data<=str2vector(line4_str,5);
when 61 => rs<='1';LCD_Data<=str2vector(line4_str,6);
when 62 => rs<='1';LCD_Data<=str2vector(line4_str,7);
when 63 => rs<='1';LCD_Data<=str2vector(line4_str,8);
when 64 => rs<='1';LCD_Data<=str2vector(line4_str,9);
when 65 => rs<='1';LCD_Data<=str2vector(line4_str,10);
when 66 => rs<='1';LCD_Data<=str2vector(line4_str,11);
when 67 => rs<='1';LCD_Data<=str2vector(line4_str,12);
when 68 => rs<='1';LCD_Data<=str2vector(line4_str,13);
when 69 => rs<='1';LCD_Data<=str2vector(line4_str,14);
when 70 => rs<='1';LCD_Data<=str2vector(line4_str,15);
when 71 => rs<='1';LCD_Data<=str2vector(line4_str,16);
when others => rs<='1';LCD_Data<=x"00";
end case;
end if;
end if;
end process;
--delay 10 ms counter
process(clk_500KHz,n_rst)
variable cnt : integer range 0 to delay_10ms-1 ;
begin
if(n_rst='0')then
cnt:=0;
delay_over<='0';
clr<='1';
elsif(clk_500KHz'event and clk_500KHz='1') then
if(LCD_cnt<=4)then
if(cnt=delay_10ms-1)then
delay_over<='1';
clr<='1';
cnt:=0;
else
delay_over<='0';
clr<='0';
if(bit_cnt=25)then
cnt:=cnt+1;
end if;
end if;
else
if(cnt=delay_1ms-1)then
delay_over<='1';
clr<='1';
cnt:=0;
else
delay_over<='0';
clr<='0';
if(bit_cnt=25)then
cnt:=cnt+1;
end if;
end if;
end if;
end if;
end process;
--output SCLK
process(clk_in,n_rst)
begin
if(n_rst='0')then
SCLK<='0';
elsif(clk_in'event and clk_in='1') then
if(en='1')then
if(bit_cnt>0 and bit_cnt<25)then
SCLK <= not clk_500KHz;
else
SCLK <= '0';
end if;
end if;
end if;
end process;
--output SID
process(clk_500KHz,n_rst)
begin
if(n_rst='0')then
SID<='0';
bit_cnt<=0;
elsif(clk_500KHz'event and clk_500KHz='1')then
if(clr='1')then
SID<='0';
bit_cnt<=0;
else
case bit_cnt is
when 0 => SID<='1';bit_cnt<=bit_cnt+1;
when 1 => SID<='1';bit_cnt<=bit_cnt+1;
when 2 => SID<='1';bit_cnt<=bit_cnt+1;
when 3 => SID<='1';bit_cnt<=bit_cnt+1;
when 4 => SID<='1';bit_cnt<=bit_cnt+1;
when 5 => SID<='0';bit_cnt<=bit_cnt+1;
when 6 => SID<=rs ;bit_cnt<=bit_cnt+1;
when 7 => SID<='0';bit_cnt<=bit_cnt+1;
when 8 => SID<=LCD_Data(7);bit_cnt<=bit_cnt+1;
when 9 => SID<=LCD_Data(6);bit_cnt<=bit_cnt+1;
when 10 => SID<=LCD_Data(5);bit_cnt<=bit_cnt+1;
when 11 => SID<=LCD_Data(4);bit_cnt<=bit_cnt+1;
when 12 => SID<='0';bit_cnt<=bit_cnt+1;
when 13 => SID<='0';bit_cnt<=bit_cnt+1;
when 14 => SID<='0';bit_cnt<=bit_cnt+1;
when 15 => SID<='0';bit_cnt<=bit_cnt+1;
when 16 => SID<=LCD_Data(3);bit_cnt<=bit_cnt+1;
when 17 => SID<=LCD_Data(2);bit_cnt<=bit_cnt+1;
when 18 => SID<=LCD_Data(1);bit_cnt<=bit_cnt+1;
when 19 => SID<=LCD_Data(0);bit_cnt<=bit_cnt+1;
when 20 => SID<='0';bit_cnt<=bit_cnt+1;
when 21 => SID<='0';bit_cnt<=bit_cnt+1;
when 22 => SID<='0';bit_cnt<=bit_cnt+1;
when 23 => SID<='0';bit_cnt<=bit_cnt+1;
when 24 => SID<='0';bit_cnt<=bit_cnt+1;
when 25 => SID<='0';bit_cnt<=bit_cnt;
when others => SID<='0';bit_cnt<=0;
end case;
end if;
end if;
end process;
end rtl;
--str2vector函数
library ieee;
use ieee.std_logic_1164.all;
package lcdchar is
function char2vector (char:in character)
return std_logic_vector;
function str2vector (str:in string;i:in integer)
return std_logic_vector;
end lcdchar;
package body lcdchar is
function char2vector (char:in character)
return std_logic_vector is
begin
case char is
when ' ' => return x"20";
when '!' => return x"21";
when '"' => return x"22";
when '#' => return x"23";
when '$' => return x"24";
when '%' => return x"25";
when '&' => return x"26";
when ''' => return x"27";
when '(' => return x"28";
when ')' => return x"29";
when '*' => return x"2a";
when '+' => return x"2b";
when ',' => return x"2c";
when '-' => return x"2d";
when '.' => return x"2e";
when '/' => return x"2f";
when '0' => return x"30";
when '1' => return x"31";
when '2' => return x"32";
when '3' => return x"33";
when '4' => return x"34";
when '5' => return x"35";
when '6' => return x"36";
when '7' => return x"37";
when '8' => return x"38";
when '9' => return x"39";
when ':' => return x"3a";
when ';' => return x"3b";
when '<' => return x"3c";
when '=' => return x"3d";
when '>' => return x"3e";
when '?' => return x"3f";
when '@' => return x"40";
when 'A' => return x"41";
when 'B' => return x"42";
when 'C' => return x"43";
when 'D' => return x"44";
when 'E' => return x"45";
when 'F' => return x"46";
when 'G' => return x"47";
when 'H' => return x"48";
when 'I' => return x"49";
when 'J' => return x"4a";
when 'K' => return x"4b";
when 'L' => return x"4c";
when 'M' => return x"4d";
when 'N' => return x"4e";
when 'O' => return x"4f";
when 'P' => return x"50";
when 'Q' => return x"51";
when 'R' => return x"52";
when 'S' => return x"53";
when 'T' => return x"54";
when 'U' => return x"55";
when 'V' => return x"56";
when 'W' => return x"57";
when 'X' => return x"58";
when 'Y' => return x"59";
when 'Z' => return x"5a";
when '[' => return x"5b";
when '\' => return x"5c";
when ']' => return x"5d";
when '^' => return x"5e";
when '_' => return x"5f";
when '`' => return x"60";
when 'a' => return x"61";
when 'b' => return x"62";
when 'c' => return x"63";
when 'd' => return x"64";
when 'e' => return x"65";
when 'f' => return x"66";
when 'g' => return x"67";
when 'h' => return x"68";
when 'i' => return x"69";
when 'j' => return x"6a";
when 'k' => return x"6b";
when 'l' => return x"6c";
when 'm' => return x"6d";
when 'n' => return x"6e";
when 'o' => return x"6f";
when 'p' => return x"70";
when 'q' => return x"71";
when 'r' => return x"72";
when 's' => return x"73";
when 't' => return x"74";
when 'u' => return x"75";
when 'v' => return x"76";
when 'w' => return x"77";
when 'x' => return x"78";
when 'y' => return x"79";
when 'z' => return x"7a";
when '{' => return x"7b";
when '|' => return x"7c";
when '}' => return x"7d";
when '~' => return x"7e";
when others =>null;
end case;
end function char2vector;
function str2vector (str:in string;i:in integer)
return std_logic_vector is
begin
return char2vector(str(i));
end function str2vector;
end package body;
--代码已验证过，相当好用
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