TMS570LC4357: in which document can i see clock source(SYSCLK ) of the ECAP ?

Hi mc b,

mc b said:

Q1 -)   i coundt find any document that shows the clock source of the ECAP module on the TMS570LC4357 mcu ? It shown as SYSCLK in the trm Figure 33-6. Counter and Synchronization Block , but what is SYSCLK ? is it VCLK ? If yes which one ?

eCAP module will use VCLK3 for capturing.

Please refer datasheet, there they clearly mentioned the input clock:

As you can see the minimum capturing width also should be at least two times the VLCK3, so that means the capturing will happen based on VCLK3.

mc b said:

Q2-) Is there any way to synchronize RTI's UC (upcounter ) and ECAP's counter (TSCTR)  ?  

No, it is not possible to synchronize RTI and ECAP.

We can only synchronize ECAP with only ePWM module.

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Thanks & regards,
Jagadish.