Setup eMIOS UC for IPWM
Hello Erwan,
thank you very much for the answers and the insight in the other thread.
Decided to start another thread, due to different topic here.
I tried to at least make the IPWM input work on eMIOS0 Ch 2 and created a little example project with channel 0 PWM output externally linked to the channel 2 input.
My new questions:
- With eMIOS 0 global prescaler at 20, resulting in internal counter frequency of 1,000,000 (Hz?), the ICU prescaler at 1 gives 1,000,000 (Hz?), is there any way to increase ICU count speed by a factor of 10 to get decimal point of PWM "percentage"?
- Is there any tool or table with recommended prescaler ratios between PWM and ICU?
In the attached patch.xml I reworked the icu_lld.c component implementation of the flag interrupt routine according to the reference manuals information.
I setup the eMIOS channel with EMIOS_CCR_MODE_IPWM flag in icu_lld_start function.
Below you see the changed part of the icu_lld_serve_interrupt function:
if ((sr & EMIOSS_FLAG) != 0U) {
icup->emiosp->CH[icup->emios_ch].S.R |= EMIOSS_FLAGC;
if (icup->config->mode == ICU_INPUT_ACTIVE_HIGH) {
if(icup->emiosp->CH[icup->emios_ch].C.R & EMIOS_CCR_MODE_IPWM && \
(icup->config->width_cb != NULL)){
icup->pe.a2_2 = (int16_t)icup->emiosp->CH[icup->emios_ch].A.R;
icup->pe.a2_1 = (int16_t)icup->emiosp->CH[icup->emios_ch].B.R;
width = (icup->pe.a2_2 - icup->pe.a2_1);
icup->width = (uint16_t)(width);
icup->config->width_cb(icup);
}
}
....
}- Substracting B1 from A2 as written on the page before gives me 50 (50% PWM) or 20 (20% PWM)
- How to get 500 instead of 50 to have a little more resolution?
Maybe somebody had the same problems while getting IPWM to work. Hope my code helps a bit.
@Mods: Please delete my last reply in How to setup IPWM on channels UC13, UC14 and UC15 with Low Level Driver component? thread, because I cannot do it myself. Thank you.
Best regards,
Christopher Seifert