diff options
| -rw-r--r-- | ports/mimxrt/hal/pwm_backport.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/ports/mimxrt/hal/pwm_backport.c b/ports/mimxrt/hal/pwm_backport.c index cea664212..a4663df4f 100644 --- a/ports/mimxrt/hal/pwm_backport.c +++ b/ports/mimxrt/hal/pwm_backport.c @@ -53,7 +53,7 @@ void PWM_SetupPwm_u16(PWM_Type *base, pwm_submodule_t subModule, pwm_signal_para // Divide the clock by the prescale value pwmClock = (srcClock_Hz / (1U << ((base->SM[subModule].CTRL & PWM_CTRL_PRSC_MASK) >> PWM_CTRL_PRSC_SHIFT))); - pulseCnt = pwmClock / pwmFreq_Hz; + pulseCnt = (pwmClock + (pwmFreq_Hz - 1) / 2) / pwmFreq_Hz; base->SM[subModule].INIT = 0; base->SM[subModule].VAL1 = pulseCnt - 1; @@ -93,9 +93,9 @@ void PWM_SetupPwmx_u16(PWM_Type *base, pwm_submodule_t subModule, // Divide the clock by the prescale value pwmClock = (srcClock_Hz / (1U << ((base->SM[subModule].CTRL & PWM_CTRL_PRSC_MASK) >> PWM_CTRL_PRSC_SHIFT))); - pulseCnt = pwmClock / pwmFreq_Hz; + pulseCnt = (pwmClock + (pwmFreq_Hz - 1) / 2) / pwmFreq_Hz; base->SM[subModule].INIT = 0; - base->SM[subModule].VAL0 = ((uint32_t)duty_cycle * pulseCnt) / PWM_FULL_SCALE; + base->SM[subModule].VAL0 = ((uint32_t)duty_cycle * pulseCnt) / PWM_FULL_SCALE - 1; base->SM[subModule].VAL1 = pulseCnt - 1; base->SM[subModule].OCTRL = (base->SM[subModule].OCTRL & ~PWM_OCTRL_POLX_MASK) | PWM_OCTRL_POLX(!invert); @@ -137,7 +137,7 @@ status_t QTMR_SetupPwm_u16(TMR_Type *base, qtmr_channel_selection_t channel, uin } // Counter values to generate a PWM signal - periodCount = (srcClock_Hz / pwmFreqHz) - 1; + periodCount = ((srcClock_Hz + (pwmFreqHz - 1) / 2) / pwmFreqHz) - 2; highCount = (periodCount * dutyCycleU16) / PWM_FULL_SCALE; lowCount = periodCount - highCount; |