serial.txt

串行口数据传输实验

library ieee;     
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity chuankou is 
port(
     clk:in std_logic;								--时钟信号
     con:out std_logic;								--控制信号
     equal:buffer std_logic;						--检测输出信号
     z:out std_logic;								--信号发生器的输出
     q:out std_logic_vector(6 downto 0));			--并行输出信号
end;

architecture behavior of chuankou is				
signal temp,temp1:std_logic:='0';
signal temp4:std_logic:='0';						--控制电路输出信号
signal temp2: std_logic_vector(6 downto 0):="0000000";
signal temp3: std_logic_vector(6 downto 0):="0000000";
signal temp5: std_logic_vector(6 downto 0):="0000000";

begin
pro1: process(clk)									--函数信号发生器
variable count: integer range 0 to 14;				--计数器
begin
if(clk'event and clk='1')then						--根据要产生的信号分配输出电平的高低
	if count=0 then 
	temp<='1';
	count:=count+1;
	elsif(count<4)then 									--4个1
	temp<='1'; 
	  count:=count+1;
	elsif(count>3 and count<7)then						--3个0
	 temp<='0'; 
	  count:=count+1;
	elsif(count>6 and count<8)then						--1个1
	 temp<='1'; 
	  count:=count+1;
	elsif(count>7 and count<10)then						--2个0
	 temp<='0'; 
	  count:=count+1;
	elsif(count>9 and count<12)then						--2个1
	 temp<='1'; 
	  count:=count+1;
	elsif(count=12)then									--1个0
	 temp<='0'; 
	 count:=count+1;
	elsif(count=13)then									--1个1
	 temp<='1'; 
	 count:=count+1;
	elsif(count=14)then									--1个0
	 temp<='0'; 
	 count:=0;											--循环结束
	end if;
end if;
temp1<=temp;
end process;
z<=temp1;

pro2: process(clk)											--串并转换
begin
if(clk'event and clk='1')then
temp2(6)<=temp2(5);
temp2(5)<=temp2(4);
temp2(4)<=temp2(3);
temp2(3)<=temp2(2);
temp2(2)<=temp2(1);
temp2(1)<=temp2(0);
temp2(0)<=temp1;
end if;
end process;
temp3<=temp2;

pro3:process(clk)												--检测电路
begin
if (temp3="1111000")then
equal<='1';
else equal<='0';
end if;
end process;

pro4:process(equal)											--控制电路
begin
if(equal'event and equal='1')then
temp4<='1';
end if;
end process;
con<=temp4;

pro5: process(clk)											--锁存输出
begin
if(clk'event and clk='1')then
if(temp4='1')then
temp5<=temp3;
else temp5<="0000000";
end if;
end if;
end process;
q<=temp5;
end;