我正在尝试使用 FSM 在 VHDL 中实现最大公约数。
这些是状态
以及有关设计的更多细节
我按照描述进行了这个实现，但在模拟过程中我没有得到正确的结果
entity fsm is
port (clk,rst: in std_logic; gt,eq,lt: in std_logic;
sel,ld,sub: out std_logic_vector(1 downto 0);
out_en: out std_logic);
end fsm;
architecture fsm of fsm is
type STATES is (S1,S2,S3,S4,S5,S6,S7,S8);
signal state: STATES;
begin
process (clk, rst)
begin
if (rst='0') then
state<=S1;
elsif (clk'event and clk='1') then
case state is
when S1 =>
sel(0) <= '1';
sel(1) <='0';
state <= S2;
when S2 =>
ld(0) <= '1';
ld(1) <= '1';
state <= S3;
when S3 =>
if(gt='1') then
state <= S4;
elsif(eq='1') then
state <= S6;
elsif(lt='1') then
state <= S7;
end if;
when S4 =>
sub(0) <= '1';
state <= S5;
when S6 =>
out_en <= '1';
when S7 =>
sub(1) <= '1';
state <= S8;
when S8 =>
sel(1) <= '1';
state <= S2;
when S5 =>
sel(0) <= '0';
state <= S2;
when others => null;
end case;
end if;
end process;
end fsm;
最后是接线模块。我不会在这里发布组件的实现，因为我认为它们在做什么是直截了当的。
library IEEE;
use IEEE.std_logic_1164.all;
entity gcd_calc is
port (
clk,rst: in std_logic;
x_i,y_i: in std_logic_vector(7 downto 0);
data_o: out std_logic_vector(7 downto 0));
end gcd_calc;
architecture struct of gcd_calc is
component mux8_2x1
port (sel: in std_logic;
inp_a,inp_b: in std_logic_vector(7 downto 0);
mout: out std_logic_vector(7 downto 0));
end component;
component reg8
port (en,clk: in std_logic;
inp: in std_logic_vector(7 downto 0);
outp: out std_logic_vector(7 downto 0));
end component;
component cmp8
port (inp_a,inp_b: in std_logic_vector(7 downto 0);
a_gt_b,a_eq_b,a_lt_b: out std_logic;
outp: out std_logic_vector(7 downto 0));
end component;
component sub8
port (en: in std_logic;
inp_a,inp_b: in std_logic_vector(7 downto 0);
outp: out std_logic_vector(7 downto 0));
end component;
component fsm
port (clk,rst: in std_logic; gt,eq,lt: in std_logic;
sel,ld,sub: out std_logic_vector(1 downto 0);
out_en: out std_logic);
end component;
signal muxx_o,regx_o,subx_o: std_logic_vector(7 downto 0);
signal muxy_o,regy_o,suby_o: std_logic_vector(7 downto 0);
signal cmp_o: std_logic_vector(7 downto 0);
signal x_sel,y_sel,x_ld,y_ld,x_sub,y_sub: std_logic;
signal x_gt_y,x_eq_y,x_lt_y,data_en: std_logic;
begin
mux_x: mux8_2x1 port map (x_sel,subx_o,x_i,muxx_o);
mux_y: mux8_2x1 port map (y_sel,y_i,suby_o,muxy_o);
reg_x: reg8 port map (x_ld,clk,muxx_o,regx_o);
reg_y: reg8 port map (y_ld,clk,muxy_o,regy_o);
cmp: cmp8 port map
(regx_o,regy_o,x_gt_y,x_eq_y,x_lt_y,cmp_o);
sub_x: sub8 port map (x_sub,regx_o,regy_o,subx_o);
sub_y: sub8 port map (y_sub,regy_o,regx_o,suby_o);
reg_out: reg8 port map (data_en,clk,cmp_o,data_o);
ctrl: fsm port map
(clk,rst,x_gt_y,x_eq_y,x_lt_y,
sel(0)=>x_sel,sel(1)=>y_sel,
ld(0)=>x_ld,ld(1)=>y_ld,
sub(0)=>x_sub,sub(1)=>y_sub,out_en=>data_en);
end struct;
编辑
模拟
