LIBRARY IEEE;                     
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_Arith.ALL;
USE IEEE.STD_LOGIC_Unsigned.ALL;

ENTITY moto IS
PORT(
clock:  IN  STD_LOGIC; 
key:  IN  STD_LOGIC_VECTOR(2 DOWNTO 0);--按键输入(key1~key3)
pwm_in:  IN  STD_LOGIC;  --产生的PWM波输入
pwm_en:  OUT STD_LOGIC;  --PWM控制使能端
duty_cycle: OUT STD_LOGIC_VECTOR(3 DOWNTO 0);--PWM占空比控制输出
motoa,motob:OUT STD_LOGIC;  --PWM波输出
led:  OUT STD_LOGIC_VECTOR(4 DOWNTO 0)
);
END;

ARCHITECTURE one OF moto IS
SIGNAL duty_cycle_io: STD_LOGIC_VECTOR(3 DOWNTO 0);
SIGNAL pwm_en_io:  STD_LOGIC;
SIGNAL count:   STD_LOGIC_VECTOR(16 DOWNTO 0);--时钟分频计数器
SIGNAL dout1,dout2,dout3:STD_LOGIC_VECTOR(2 DOWNTO 0);--消抖寄存器
SIGNAL moto_dir:  STD_LOGIC;--电机正反转
SIGNAL k_debounce:  STD_LOGIC_VECTOR(2  DOWNTO 0);--按键消抖输出
SIGNAL clk:    STD_LOGIC;--分频时钟
SIGNAL key_edge:  STD_LOGIC_VECTOR(2  DOWNTO 0);

BEGIN
led<=NOT (pwm_en_io & duty_cycle_io);--LED输出状态指示
pwm_en <= pwm_en_io;
duty_cycle <= duty_cycle_io;

PROCESS(clock)
BEGIN
 IF RISING_EDGE(clock) THEN
  IF count<120000 THEN 
   count<=count+1;
   clk<='0';
  ELSE
   count<=B"0_0000_0000_0000_0000";
   clk<='1';
  END IF;
 END IF;
END PROCESS;
 -------------------------------------------<<按键消抖部分
PROCESS (clock)
BEGIN
 IF RISING_EDGE(clock) THEN
  IF clk='1' THEN
   dout1<=key;
   dout2<=dout1;
   dout3<=dout2;
  END IF;
 END IF;
END PROCESS;

PROCESS (clock)
BEGIN
 IF RISING_EDGE(clock) THEN
  k_debounce<=dout1 OR dout2 OR dout3;--按键消抖输出.
 END IF;
END PROCESS;
key_edge<=NOT (dout1 OR dout2 OR dout3) AND k_debounce;

PROCESS(clock)--按键1 控制电动机速度
BEGIN
 IF RISING_EDGE(clock) THEN
  IF key_edge(0)='1' THEN
   duty_cycle_io<=duty_cycle_io+1;
  END IF;
 END IF;
END PROCESS;

PROCESS(clock)--按键2，控制电动机启动、停止
BEGIN
 IF RISING_EDGE(clock) THEN
  IF key_edge(1)='1' THEN
   pwm_en_io<=NOT pwm_en_io;
  END IF;
 END IF;
END PROCESS;

PROCESS(clock)--按键3，控制电动机正/反转
BEGIN
 IF RISING_EDGE(clock) THEN
  IF key_edge(2)='1' THEN
   moto_dir <=NOT moto_dir;
  END IF;
 END IF;
END PROCESS;
motoa<=pwm_in WHEN moto_dir='1' ELSE '0';
motob<='0' WHEN moto_dir='1' ELSE pwm_in;

END;