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这个确实不好懂,对齐一下,仿真不难的:sleepy:
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY m IS
PORT(
clr,clk,load:IN STD_LOGIC;
din :IN STD_LOGIC_VECTOR(3 downto 0);
dout :OUT STD_LOGIC
)
END m;
ARCHITECTURE bhv OF m IS
SIGNAL rfsr:STD_LOGIC_VECTOR(3 downto 0);
-- SIGNAL tmp:STD_LOGIC;
BEGIN ROCESS(clr,clk,load,din) BEGIN
IF(clr='1') THEN
rfsr <=(OTHERS=>'0');
ELSIF(clk'EVENT AND clk='1') THEN IF(load='1')THEN
rfsr<= din;
ELSE
rfsr(3) <=rfsr(0)XOR rfsr(1);
rfsr(2 downto 0)<=rfsr(3 downto 1);
dout<= rfsr(0);
END IF;
END IF;
END PROCESS
END bhv; |
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