s_machine.vhd

来自「right.vhd 序列发生器 s_machine.vhd 序列检测器 波形」· VHDL 代码 · 共 85 行

LIBRARY IEEE;
USE ieee.std_logic_1164.all;
ENTITY s_machine IS
	PORT(clk,reset		:IN	STD_LOGIC;
		 state_input	:BUFFER STD_LOGIC;--串行序列输入
         serial         :IN STD_LOGIC;--选择输入序列
		 --input			:IN STD_LOGIC;
		 comb_output	:OUT STD_LOGIC; --检测结果输出
		 state_output	:OUT STD_LOGIC_VECTOR(0 to 3)
		);
END s_machine;

ARCHITECTURE behav OF s_machine IS
	TYPE FSM_ST IS (s0,s1,s2,s3,s4,s5,s6,s7);
	SIGNAL current_state,next_state:FSM_ST;
	--SIGNAL state_input:std_logic;

	COMPONENT right
		PORT(clkr,wr:IN	 std_logic;
	  		 CO		:OUT std_logic
 	 		);
    END COMPONENT;
    
BEGIN
	REG:PROCESS(reset,clk)
	BEGIN 
		IF (reset = '1') THEN current_state <= s0;
		ELSIF (clk = '1' AND clk'EVENT) THEN
			current_state <= next_state;
		END IF;
	END PROCESS;
 
 U1:right PORT MAP(clkr=>clk,wr=>serial,CO=>state_input);



 COM:PROCESS(current_state)
	BEGIN
		CASE current_state IS

			WHEN s0=> comb_output<='0';state_output <= "0000";
				IF state_input = '0' THEN next_state<=s0;
				ELSE next_state<=s1;
				END IF;

			WHEN s1=> comb_output<='0';state_output <= "0001";
				IF state_input = '0' THEN next_state<=s0;
				ELSE next_state<=s2;
				END IF;

			WHEN s2=> comb_output<='0';state_output <= "0010";
				IF state_input = '0' THEN next_state<=s0;
				ELSE next_state<=s3;
				END IF;

			WHEN s3=> comb_output<='0';state_output <= "0011";
				IF state_input = '1' THEN next_state<=s3;
				ELSE next_state<=s4;
				END IF;

			WHEN s4=> comb_output<='0';state_output <= "0100";
				IF state_input = '1' THEN next_state<=s1;
				ELSE next_state<=s5;
				END IF;

			WHEN s5=> comb_output<='0';state_output <= "0101";
				IF state_input = '0' THEN next_state<=s0;
				ELSE next_state<=s6;
				END IF;

			WHEN s6=> comb_output<='0';state_output <= "0110";
				IF state_input = '1' THEN next_state<=s2;
				ELSE next_state<=s7;
				END IF;

			WHEN s7=> comb_output<='1';state_output <= "0111";
				IF state_input = '1' THEN next_state<=s1;
				ELSE next_state<=s0;
				END IF;
				
		END CASE;
 END PROCESS;
END behav;