原创 TIMx 的PWM波输出,ST的TIMx example4

ST的example4 产生PWM波,无中断程序
/* Includes ------------------------------------------------------------------*/
#include "stm32f10x_lib.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;
u16 CCR1_Val = 0x1F4;
u16 CCR2_Val = 0x177;
u16 CCR3_Val = 0xFA;
u16 CCR4_Val = 0x7D;
ErrorStatus HSEStartUpStatus;
  
/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);
   
/* Private functions ---------------------------------------------------------*/

int main(void)
{
#ifdef DEBUG
  debug();
#endif

  /* System Clocks Configuration */
  RCC_Configuration();

  /* NVIC Configuration */
  NVIC_Configuration();
 
  /* GPIO Configuration */
  GPIO_Configuration();

/* -----------------------------------------------------------------------
  TIM3 Configuration: generate 4 PWM signals with 4 different duty cycles:
  TIM3CLK = 36 MHz, Prescaler = 0x0, TIM3 counter clock = 36 MHz
  TIM3 ARR Register = 0x3E7 => TIM3 Frequency = TIM3 counter clock/(ARR + 1)
  TIM3 Frequency = 36 KHz.
  TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR)* 100 = 50%
  TIM3 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR)* 100 = 37.5%
  TIM3 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR)* 100 = 25%
  TIM3 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR)* 100 = 12.5%
----------------------------------------------------------------------- */
 
  /* Time base configuration */
 TIM_TimeBaseStructure.TIM_Period = 0x3E7;             //0x3E7=999, 从0到999相当于计数1000次,到了999再从0开始计数
  TIM_TimeBaseStructure.TIM_Prescaler = 0x00;      
  TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;   
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  // PWM mode1, upcounting mode下, CNT

  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

  /* PWM1 Mode configuration: Channel1 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;         
  TIM_OCInitStructure.TIM_Channel = TIM_Channel_1;         
  TIM_OCInitStructure.TIM_Pulse = CCR1_Val;             //0x1F4=500, Duty cycle="500/1000"=0.5
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
   
  TIM_OCInit(TIM3, &TIM_OCInitStructure);

  TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel2 */
  TIM_OCInitStructure.TIM_Channel = TIM_Channel_2;         
  TIM_OCInitStructure.TIM_Pulse = CCR2_Val;             //0x177=375, D="375/1000"=0.375
 
  TIM_OCInit(TIM3, &TIM_OCInitStructure);

  TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel3 */
  TIM_OCInitStructure.TIM_Channel = TIM_Channel_3;         
  TIM_OCInitStructure.TIM_Pulse = CCR3_Val;             //0xFA=250, D="375/1000"=0.25

  TIM_OCInit(TIM3, &TIM_OCInitStructure);

  TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel4 */
  TIM_OCInitStructure.TIM_Channel = TIM_Channel_4;         
  TIM_OCInitStructure.TIM_Pulse = CCR4_Val;            //0x177=125, D="375/1000"=0.125

  TIM_OCInit(TIM3, &TIM_OCInitStructure);

  TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);
 
  TIM_ARRPreloadConfig(TIM3, ENABLE);

  /* TIM3 enable counter */
  TIM_Cmd(TIM3, ENABLE);

  while(1)
  {
  } 
}