ST STM32L0x3

Code examples RM0367
996/1043 RM0367 Rev 7
/* (2) Enable the counter by writing CEN=1 in the TIMx_CR1 register. */
TIMx->SMCR |= TIM_SMCR_ETPS_0 | TIM_SMCR_ECE; /* (1) */
TIMx->CR1 |= TIM_CR1_CEN; /* (2) */
A.11.3 Input capture configuration code example
/* (1) Select the active input TI1 (CC1S = 01),
program the input filter for 8 clock cycles (IC1F = 0011),
select the rising edge on CC1 (CC1P = 0, reset value)
and prescaler at each valid transition (IC1PS = 00, reset value) */
/* (2) Enable capture by setting CC1E */
/* (3) Enable interrupt on Capture/Compare */
/* (4) Enable counter */
TIMx->CCMR1 |= TIM_CCMR1_CC1S_0 \
| TIM_CCMR1_IC1F_0 | TIM_CCMR1_IC1F_1; /* (1 */
TIMx->CCER |= TIM_CCER_CC1E; /* (2) */
TIMx->DIER |= TIM_DIER_CC1IE; /* (3) */
TIMx->CR1 |= TIM_CR1_CEN; /* (4) */
A.11.4 Input capture data management code example
This code must be inserted in the timer interrupt subroutine.
if ((TIMx->SR & TIM_SR_CC1IF) != 0)
{
if ((TIMx->SR & TIM_SR_CC1OF) != 0) /* Check the overflow */
{
/* Overflow error management */
gap = 0; /* Reinitialize the laps computing */
TIMx->SR = ~(TIM_SR_CC1OF | TIM_SR_CC1IF); /* Clear the flags */
return;
}
if (gap == 0) /* Test if it is the first rising edge */
{
counter0 = TIMx->CCR1; /* Read the capture counter which clears the
CC1ICF */
gap = 1; /* Indicate that the first rising edge has yet been detected */
}
else
{
counter1 = TIMx->CCR1;
/* Read the capture counter which clears the
CC1ICF */
if (counter1 > counter0) /* Check capture counter overflow */
{
Counter = counter1 - counter0;
}
else
{