[VHDL代码]LCD1602驱动.docx

VHDL代码LCD1602驱动library IEEE;use IEEE.STD_LOGIC_1164.ALL;use IEEE.STD_LOGIC_ARITH.ALL;use IEEE.STD_LOGIC_UNSIGNED.ALL;entity LCD1602 isPort ( Clk : in std_logic; -状态机时钟信号，同时也是液晶时钟信号，其周期应该满足液晶数据的建立时间Sec_low,Sec_high,Min_low,Min_high,Hour_low,Hour_high: in std_logic_vector(3 downto 0);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;architecture Behavioral of LCD1602 istype STATE_TYPE is (START,write_C,write_D,WRITE_BYTE_C,WRITE_BYTE_D,wait_3m1,wait_3m2,wait_5m1,wait_5m2,wait_100m);type MY_ARRAY1 is array(0 to 4) of std_logic_vector(7 downto 0);type MY_ARRAY2 is array(0 to 7) of std_logic_vector(7 downto 0);-长度为14的 8位/字数组constant c_d: MY_ARRAY1:=(x38,x0c,x06,x01,x84);signal d_d: MY_ARRAY2:=(x20,x20,x3A,x20,x20,x3A,x20,x20);signal STATE: STATE_TYPE:=START;signal w_c_flag : integer range 0 to 2:=0;signal w_d_flag : integer range 0 to 2:=0;signal write_c_cnt : integer range 0 to 5:=0;signal write_d_cnt : integer range 0 to 8:=0;signal cnt : integer range 0 to 10000:=0; signal count : integer range 0 to 10000:=0;begin LCD_RW = 0 ; -写数据d_d(0)=0000&Hour_high+x30;d_d(1)=0000&Hour_low+x30;d_d(3)=0000&Min_high+x30;d_d(4)=0000&Min_low+x30;d_d(6)=0000&Sec_high+x30;d_d(7) LCD_EN=0;w_c_flag=0;w_d_flag=0;write_c_cnt=0;write_d_cnt=0;STATEcase write_c_cnt is when 0 to 4= STATE write_c_cnt=4;STATEif(w_c_flag=0) thenLCD_RS=0;LCD_Data=c_d(write_c_cnt);w_c_flag=1;STATE=wait_3m1;elsif(w_c_flag=1) thenLCD_EN=1; w_c_flag=2;STATE=wait_5m1;elsif(w_c_flag=2) thenLCD_EN=0;w_c_flag=0;write_c_cnt=write_c_cnt+1;STATEcase write_d_cnt is when 0 to 7= STATE write_d_cnt=0;STATEif(w_d_flag=0) thenLCD_RS=1;LCD_Data=d_d(write_d_cnt);w_d_flag=1;STATE=wait_3m2;elsif(w_d_flag=1) thenLCD_EN=1; w_d_flag=2;STATE=wait_5m2;elsif(w_d_flag=2) thenLCD_EN=0;w_d_flag=0;write_d_cnt=write_d_cnt+1;STATEif (cnt=3) then STATE=WRITE_BYTE_C; cnt=0; else cnt=cnt+1; STATE if (cnt=5) then STATE=WRITE_BYTE_C; cnt=0; else cnt=cnt+1; STATE if (cnt=3) then STATE=WRITE_BYTE_D; cnt=0; else cnt=cnt+1; STATE if (cnt=5) then STATE=WRITE_BYTE_D; cnt=0; else cnt=cnt+1; STATE if (cnt=1