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Merge pull request #1150 from ohagendorf/stm32f4_pwm_frequency 

STM32F4xx - correction of PWM frequency calculation
pull/1149/merge
Martin Kojtal 2015-06-03 07:56:49 +01:00
parent 7a1d25e3df 0abf0f3e41
commit 83c82b06fc
1 changed files with 71 additions and 2 deletions
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73
libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32F4/pwmout_api.c
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@ -165,7 +165,9 @@ void pwmout_period_ms(pwmout_t* obj, int ms)
void pwmout_period_us(pwmout_t* obj, int us)
{
TimHandle.Instance = (TIM_TypeDef *)(obj->pwm);
RCC_ClkInitTypeDef RCC_ClkInitStruct;
uint32_t PclkFreq;
uint32_t APBxCLKDivider;
float dc = pwmout_read(obj);
__HAL_TIM_DISABLE(&TimHandle);
@ -173,8 +175,75 @@ void pwmout_period_us(pwmout_t* obj, int us)
// Update the SystemCoreClock variable
SystemCoreClockUpdate();
HAL_RCC_GetClockConfig(&RCC_ClkInitStruct, &PclkFreq);
switch (obj->pwm) {
case PWM_1:
PclkFreq = HAL_RCC_GetPCLK2Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB2CLKDivider;
break;
case PWM_2:
PclkFreq = HAL_RCC_GetPCLK1Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB1CLKDivider;
break;
case PWM_3:
PclkFreq = HAL_RCC_GetPCLK1Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB1CLKDivider;
break;
case PWM_4:
PclkFreq = HAL_RCC_GetPCLK1Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB1CLKDivider;
break;
#if defined(TIM8_BASE)
case PWM_8:
PclkFreq = HAL_RCC_GetPCLK2Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB2CLKDivider;
break;
#endif
case PWM_9:
PclkFreq = HAL_RCC_GetPCLK2Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB2CLKDivider;
break;
case PWM_10:
PclkFreq = HAL_RCC_GetPCLK2Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB2CLKDivider;
break;
case PWM_11:
PclkFreq = HAL_RCC_GetPCLK2Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB2CLKDivider;
break;
#if defined(TIM13_BASE)
case PWM_13:
PclkFreq = HAL_RCC_GetPCLK1Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB1CLKDivider;
break;
#endif
#if defined(TIM14_BASE)
case PWM_14:
PclkFreq = HAL_RCC_GetPCLK1Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB1CLKDivider;
break;
#endif
default:
return;
}
TimHandle.Init.Period = us - 1;
TimHandle.Init.Prescaler = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 µs tick
if (APBxCLKDivider == RCC_HCLK_DIV1)
TimHandle.Init.Prescaler = (uint16_t)((PclkFreq*2) / 1000000) - 1; // 1 µs tick
else
TimHandle.Init.Prescaler = (uint16_t)((PclkFreq) / 1000000) - 1; // 1 µs tick
TimHandle.Init.ClockDivision = 0;
TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;
HAL_TIM_PWM_Init(&TimHandle);