STM32F4库函数初始化系列：PWM输出

  1 void _TIM4_Configuration(void)
  2 {
  3   /* TIM4 Configuration ---------------------------------------------------
  4      Generates 7 PWM signals with 4 different duty cycles:
  5      TIM4CLK = 72 MHz, Prescaler = 0, TIM4 counter clock = 72 MHz
  6      TIM4 frequency = TIM4CLK/(TIM4_Period + 1) = 17.57 KHz
  7      - TIM4 Channel1 & Channel1N duty cycle = TIM4->CCR1 / (TIM4_Period + 1) = 50% 
  8      - TIM4 Channel2 & Channel2N duty cycle = TIM4->CCR2 / (TIM4_Period + 1) = 37.5% 
  9      - TIM4 Channel3 & Channel3N duty cycle = TIM4->CCR3 / (TIM4_Period + 1) = 25%
 10      - TIM4 Channel4 duty cycle = TIM4->CCR4 / (TIM4_Period + 1) = 12.5% 
 11      ----------------------------------------------------------------------- */
 12   TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
 13   TIM_OCInitTypeDef  TIM_OCInitStructure;
 14 
 15   /* Time Base configuration */ 
 16   TIM_TimeBaseStructure.TIM_Prescaler = (SystemCoreClock/880000/2)-1;  //2000000
 17   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
 18   TIM_TimeBaseStructure.TIM_Period = 1023;
 19   TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV4;
 20   TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
 21 
 22   TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
 23 
 24   TIM_ARRPreloadConfig(TIM4, ENABLE);
 25 
 26   TIM_OCStructInit(&TIM_OCInitStructure);
 27 
 28   /* Channel 1, 2,3 and 4 Configuration in PWM mode */
 29   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
 30   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
 31   TIM_OCInitStructure.TIM_Pulse = 0;
 32   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
 33   TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
 34 
 35   TIM_OC1Init(TIM4, &TIM_OCInitStructure);
 36   TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);
 37 
 38   TIM_OCInitStructure.TIM_Pulse = 0;
 39   TIM_OC2Init(TIM4, &TIM_OCInitStructure);
 40   TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);
 41 
 42   TIM_OCInitStructure.TIM_Pulse = 0;
 43   TIM_OC3Init(TIM4, &TIM_OCInitStructure);
 44   TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);
 45 
 46   TIM_OCInitStructure.TIM_Pulse = 0;
 47   TIM_OC4Init(TIM4, &TIM_OCInitStructure);
 48   TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);
 49 
 50   /* TIM4 counter enable */
 51   TIM_Cmd(TIM4, ENABLE);
 52 
 53   /* TIM4 Main Output Enable */
 54   TIM_CtrlPWMOutputs(TIM4, ENABLE);  
 55 }
 56 
 57 void _TIM8_Configuration(void)
 58 {
 59   /* TIM8 Configuration ---------------------------------------------------
 60      Generates 7 PWM signals with 4 different duty cycles:
 61      TIM8CLK = 72 MHz, Prescaler = 0, TIM8 counter clock = 72 MHz
 62      TIM8 frequency = TIM8CLK/(TIM8_Period + 1) = 17.57 KHz
 63      - TIM8 Channel1 & Channel1N duty cycle = TIM8->CCR1 / (TIM8_Period + 1) = 50% 
 64      - TIM8 Channel2 & Channel2N duty cycle = TIM8->CCR2 / (TIM8_Period + 1) = 37.5% 
 65      - TIM8 Channel3 & Channel3N duty cycle = TIM8->CCR3 / (TIM8_Period + 1) = 25%
 66      - TIM8 Channel4 duty cycle = TIM8->CCR4 / (TIM8_Period + 1) = 12.5% 
 67      ----------------------------------------------------------------------- */
 68   TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
 69   TIM_OCInitTypeDef  TIM_OCInitStructure;
 70 
 71   /* Time Base configuration */ 
 72   TIM_TimeBaseStructure.TIM_Prescaler = (SystemCoreClock/880000)-1;  //2000000
 73   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
 74   TIM_TimeBaseStructure.TIM_Period = 1023;
 75   TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV4;
 76   TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
 77 
 78   TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure);
 79 
 80   TIM_ARRPreloadConfig(TIM8, ENABLE);
 81 
 82   TIM_OCStructInit(&TIM_OCInitStructure);
 83 
 84   /* Channel 1, 2,3 and 4 Configuration in PWM mode */
 85   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
 86   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
 87   TIM_OCInitStructure.TIM_Pulse = 0;
 88   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
 89   TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
 90 
 91   TIM_OC1Init(TIM8, &TIM_OCInitStructure);
 92   TIM_OC1PreloadConfig(TIM8, TIM_OCPreload_Enable);
 93 
 94   TIM_OCInitStructure.TIM_Pulse = 0;
 95   TIM_OC2Init(TIM8, &TIM_OCInitStructure);
 96   TIM_OC2PreloadConfig(TIM8, TIM_OCPreload_Enable);
 97 
 98   TIM_OCInitStructure.TIM_Pulse = 0;
 99   TIM_OC3Init(TIM8, &TIM_OCInitStructure);
100   TIM_OC3PreloadConfig(TIM8, TIM_OCPreload_Enable);
101 
102   TIM_OCInitStructure.TIM_Pulse = 0;
103   TIM_OC4Init(TIM8, &TIM_OCInitStructure);
104   TIM_OC4PreloadConfig(TIM8, TIM_OCPreload_Enable);
105 
106   /* TIM8 counter enable */
107   TIM_Cmd(TIM8, ENABLE);
108 
109   /* TIM8 Main Output Enable */
110   TIM_CtrlPWMOutputs(TIM8, ENABLE);  
111 }
112 
113 TIM_SetCompare1( TIM4,500 );