D – триггер

Исследование работы триггера.

Цель работы:

Изучение принципов функционирования простейшего конечного автомата.

 

RS-триггер

library ieee;

use ieee.std_logic_1164.all;

entity trs is

generic (delay:time:=2 ns);

port(

r,s: in std_logic;

q,nq: out std_logic

);

end trs;

architecture arch of trs is

signal p,np: std_logic;

begin

process (r,s)

begin

if r='0' and s='0' then p<='1' after delay;

np<='1' after delay;

elsif r='0' and s='1' then p<='0' after 2*delay;

np<='1' after delay;

elsif r='1' and s='0' then p<='1' after delay;

np<='0' after 2*delay;

elsif r='1' and s='1'then p<='X'; np<='X';

end if;

end process;

q<=p;

nq<=np;

end arch;

 

 

 

D – триггер

library ieee;

use ieee.std_logic_1164.all;

entity tr is

port(

data_i: in std_logic;

clk_i: in std_logic;

s : in std_logic;

r : in std_logic;

data_out: out std_logic

);

end tr;

architecture arch of tr is

begin

process (clk_i,s,r)

begin

if r='0' then

data_out<='0';

elsif s='0' then

data_out<='1';

elsif(rising_edge(clk_i)) then

data_out <= data_i;

end if;

end process;

end arch;