VHDL 1602 第二行只显示点阵

只看该作者 · 2014-8-27 11:24

第一行显示正常，第二行显示是点阵
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity LCD1602_1 is
Port ( CLK : in std_logic;
      Reset : in std_logic;
      LCD_RS : out std_logic; --寄存器选择信号
      LCD_RW : out std_logic; --液晶读写信号
      LCD_EN : out std_logic; --液晶时钟信号
      LCD_Data : out std_logic_vector(7 downto 0)); --液晶数据信号
end LCD1602_1;

architecture Behavioral of LCD1602_1 is
type state is (set_dlnf,set_cursor,set_dcb,set_cgram,write_cgram,set_ddram,write_LCD_Data);
signal Current_State:state;
signal Clk_Out : std_logic;
signal LCD_Clk : std_logic;

begin

process(CLK)--分频进程，CLK输入，CLK_Out输出，50MHz输入，125Hz输出，8ms
  variable n1:integer range 0 to 19999;
begin
if rising_edge(CLK) then
   if n1<19999 then n1:=n1+1;
   else n1:=0;
         Clk_Out<=not Clk_Out;
   end if;
end if;
end process;

LCD_RW <= '0' ; --RW='0';写入设置
LCD_EN <= Clk_Out ; --用125Hz作为LCD的使能，也作为LCD的时钟
LCD_Clk <= Clk_Out; --用125Hz作为LCD的时钟

process(LCD_Clk,Reset,Current_State) --状态机控制显示
variable cnt1: std_logic_vector(4 downto 0):="00000";
begin
  if Reset='0'then Current_State<=set_dlnf; -- Reset就清屏，Reset接出用一个按钮作为复位按键即可，按下就为'0'复位。
               cnt1:="11110";
--                LCD_RS<='0';
  elsif rising_edge(LCD_Clk) then Current_State <= Current_State ; --LCD_RS <= '0';

   case Current_State is
   when set_dlnf=> LCD_RS<='0';cnt1:="00000";
                  LCD_Data<="00000001";  --  /*清除显示*/ 清屏指令
                  Current_State<=set_cursor;

   when set_cursor=> LCD_RS<='0';LCD_Data<="00111000";--/*设置8位格式,2行,5*7*/
                     Current_State<=set_dcb;

   when set_dcb=>  LCD_RS<='0';LCD_Data<="00001100"; --/*整体显示,关光标,不闪烁*/
                  Current_State<=set_cgram;

   when set_cgram=> LCD_RS<='0';LCD_Data<="00000110";  --/*显示移动格式，看最后两位，10表示光标右移
                     Current_State<=set_ddram;
   when set_ddram=> LCD_RS<='0';
IF CNT1<"01111" THEN CNT1:=CNT1+1;       --主体显示，写显示地址DDRam（RS='0'）
                     ELSE CNT1:="00000";
                     END IF;
                     IF CNT1<="01111" THEN LCD_Data <="11000000"+cnt1;
                     END IF;
                     Current_State<=write_cgram;
when write_cgram=> LCD_RS<='1'; --主体显示，写显示内容
                     LCD_Data<="01010000" +cnt1;
                     Current_State<=write_LCD_Data;
   when write_LCD_Data=> LCD_RS<='0';LCD_Data<="00000000";
                        Current_State<=set_cursor;

   when others => null;
   end case;
end if;

end process;

end Behavioral;