基于EDA开发平台的红外遥控电机转速电路设计(9)
USE IEEE.STD_LOGIC_Arith.ALL;
USE IEEE.STD_LOGIC_Unsigned.ALL;
ENTITY moto_test IS
PORT(
clock_48M: IN STD_LOGIC; --系统时钟(48MHz)
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_test IS
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
PROCESS(clock_48M)
VARIABLE count: STD_LOGIC_VECTOR(4 DOWNTO 0):="00000";--时钟分频计数器
BEGIN
IF RISING_EDGE(clock_48M) THEN
IF count<20 THEN --(仿真)
count:=count+1;
clk<='0';
ELSE
count:=B"0_0000"; --(仿真)
clk<='1';
END IF;
END IF;
END PROCESS;
PROCESS(clock_48M)--按键1 控制电动机速度
VARIABLE duty_cycle_io: STD_LOGIC_VECTOR(3 DOWNTO 0):="0000";
VARIABLE pwm_en_io: STD_LOGIC :='0';
BEGIN
IF (RISING_EDGE(clock_48M)) THEN
IF (key(0)='1') THEN
duty_cycle_io:=duty_cycle_io+1;
END IF;
IF(key(1)='1') THEN --按键2，控制电动机启动、停止
pwm_en_io:='1';
ELSE
pwm_en_io:='0';
END IF;
END IF;
duty_cycle <= duty_cycle_io;
pwm_en <= pwm_en_io;
led<=NOT (pwm_en_io & duty_cycle_io);--LED输出状态指示
END PROCESS;
PROCESS(clock_48M)--按键3，控制电动机正/反转
BEGIN
IF RISING_EDGE(clock_48M) THEN
IF key(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;
（3）VHDL程序分析