序列检测器的vhdl状态机设计
时间: 2023-08-07 14:29:14 浏览: 43
序列检测器通常是通过状态机来实现的,下面是一个简单的 VHDL 状态机设计:
```vhdl
entity sequence_detector is
port (
clk : in std_logic;
reset : in std_logic;
input : in std_logic;
output : out std_logic
);
end entity;
architecture behavioral of sequence_detector is
type state_type is (S0, S1, S2, S3, S4);
signal state : state_type;
begin
process (clk, reset)
begin
if reset = '1' then
state <= S0;
output <= '0';
elsif rising_edge(clk) then
case state is
when S0 =>
if input = '1' then
state <= S1;
else
state <= S0;
end if;
when S1 =>
if input = '0' then
state <= S2;
else
state <= S1;
end if;
when S2 =>
if input = '1' then
state <= S3;
else
state <= S0;
end if;
when S3 =>
if input = '1' then
state <= S4;
output <= '1';
else
state <= S0;
end if;
when S4 =>
state <= S0;
end case;
end if;
end process;
end architecture;
```
这个状态机实现了一个简单的序列检测器,检测输入序列 "101"。当输入序列为 "101" 时,输出被设置为 '1'。当输入序列不是 "101" 时,输出为 '0'。状态机的状态转移由输入序列的逻辑决定,当状态机转移到 S4 状态时,输出被设置为 '1'。当状态机回到初始状态 S0 时,输出被重置为 '0'。