1602为什么可以直接显示字符

液晶分很多种，一种是段式液晶、一种是单色点阵lcm，另外一种是tft彩屏。

南京罗姆液晶公司都有卖的，您可以咨询下他们。

段式lcd您要点亮比较容易，只要你的字体是同一段，你让那段是低电平就可以。。

lcm的可以选择带字库的，您直接写程序调用就可以。

tft彩屏的话，就要做好驱动，下载一些字库，然后写程序调用！！！

求LCD的VHDL显示模块，用1602的芯片

library IEEE; use IEEE.STD_LOGIC_1164.ALL; use IEEE.STD_LOGIC_ARITH.ALL; use IEEE.STD_LOGIC_UNSIGNED.ALL; entity LCD1602 is Port ( CLK : in std_logic; Reset : in std_logic; LCD_RS : out std_logic; LCD_RW : out std_logic; LCD_EN : out std_logic; data : out std_logic_vector(3 downto 0)); end LCD1602; architecture Behavioral of LCD1602 is type iState is ( Write_instr, --写命令字 Write_DataUP4_1, --写LCD一线高4位 Write_DataDown4_1, --写LCD一线低4位 Set_DDRamAddUp, --设置DDRam地址高4位 Set_DDRamAddDown, --设置DDRam地址低4位 Write_DataUP4_2, --写LCD二线高4位 Write_DataDown4_2 --写LCD二线低4位 ); signal State:iState; type Ram is array(0 to 15) of std_logic_vector(7 downto 0); constant MyRamUp:Ram:=(x46,x68,x69,x73,x20,x49,x73,x20,x4d,x79,x20,x46,x69,x72,x73,x74); --This Is My First constant MyRamDown:Ram:=(x20,x20,x46,x50,x47,x41,x20,x50,x72,x6f,x67,x72,x61,x6d,x20,x20); --FPGA Program signal LCD_Clk : std_logic :='0'; signal datacnt : integer range 0 to 15:=0; begin LCD_RW <= '0'; LCD_EN <= LCD_Clk; process(CLK) --20000分频,满足时序要求 variable n1:integer range 0 to 19999; begin if rising_edge(CLK) then if n1<19999 then n1:=n1+1; else n1:=0; LCD_Clk<=not LCD_Clk; end if; end if; end process; process(LCD_Clk,state,reset) begin if Reset='0' then state<=Write_instr; LCD_RS <= '0'; elsif rising_edge(LCD_Clk) then case state is when Write_instr=> --写命令字到LCD控制器 LCD_RS<='0'; if(datacnt=0)then data<=0011; --0011 datacnt<=datacnt+1; elsif(datacnt=1)then data<=0011; --0011 datacnt<=datacnt+1; elsif(datacnt=2)then data<=0011; --0011 datacnt<=datacnt+1; elsif(datacnt=3)then data<=0010; --0010 datacnt<=datacnt+1; elsif(datacnt=4)then --0x28 : 0010 1000 =>功能设置 data<=0010; datacnt<=datacnt+1; elsif(datacnt=5)then data<=1000; datacnt<=datacnt+1; elsif(datacnt=6)then --0x06 : 0000 0110 =>模式设定 data<=0000; datacnt<=datacnt+1; elsif(datacnt=7)then data<=0110; datacnt<=datacnt+1; elsif(datacnt=8)then --0x0c : 0000 1100 =>显示设定 data<=0000; datacnt<=datacnt+1; elsif(datacnt=9)then data<=1100; datacnt<=datacnt+1; elsif(datacnt=10)then --0x10 : 1000 0000 =>00H 设定读写地址位 data<=1000; datacnt<=datacnt+1; else data<=0000; datacnt<=0; state<=Write_DataUP4_1; end if; when Write_DataUP4_1=> LCD_RS<='1'; data <= MyRamUp(datacnt)(7 downto 4); state <= Write_DataDown4_1; when Write_DataDown4_1=> if datacnt=15 then data <= MyRamUp(datacnt)(3 downto 0); datacnt<=0; state <=Set_DDRamAddUp; else data <= MyRamUp(datacnt)(3 downto 0); datacnt<=datacnt+1; state <=Write_DataUP4_1; end if; when Set_DDRamAddUp=> --0xc0 : 1100 0000=>40H 设定读写地址位 LCD_RS<='0'; data<=1100; state<=Set_DDRamAddDown; when Set_DDRamAddDown=> data<=0000; state<=Write_DataUP4_2; when Write_DataUP4_2=> LCD_RS<='1'; data <= MyRamDown(datacnt)(7 downto 4); state <= Write_DataDown4_2; when Write_DataDown4_2=> if datacnt=15 then data <= MyRamDown(datacnt)(3 downto 0); datacnt<=0; state <=Write_DataUP4_1; else data <= MyRamDown(datacnt)(3 downto 0); datacnt<=datacnt+1; state <=Write_DataUP4_2; end if; when others=> state<=Write_instr; end case; end if; end process; end Behavioral;