Tool/software:
Hello everyone,
I am currently working with the TMS320F280045 to control high-resolution PWM (HRPWM). According to Section 18.4.7.2 of the Technical Reference Manual, the one-shot load mode should not be used when high-resolution mode is enabled. Specifically, it states:
One-shot load mode should NOT be used when high-resolution mode is enabled.
Furthermore, Section 18.7.2 mentions:
TBPRDHR cannot be used with Global load. If a high-resolution period must be changed in the application, users must write to the individual period registers from an ePWM ISR (The ISR must be synchronous with the PWM switching period), where the Global Load One-Shot bit is also written to.
My questions are:
- Is the Global Load mode completely unusable in high-resolution mode, or is it only the TBPRDHR register that cannot use the Global Load?
- If Global Load cannot be used in high-resolution mode, are there any other methods to achieve synchronized updates of HRPWM?
My current requirement is to synchronously update multiple HRPWM registers, including TBPRDHR and CMPAHR/CMPBHR, to achieve synchronized waveforms across multiple channels.
In this scenario, is it feasible to use the Trip Zone (TZ) module’s synchronization mechanism? Or are there other recommended methods to achieve synchronized updates?
Thank you very much!
Additional Information: I have attempted the following configurations but encountered issues with synchronization precision:
- Using the EPWM synchronization chain to synchronize multiple channels, but found significant synchronization errors in high-resolution applications.
- Attempting to manually update registers via software interrupts (ISR), but due to the ISR response time, achieving high-precision synchronization has been difficult.
I am looking for specific suggestions and example codes on how to achieve synchronized updates in high-resolution PWM mode.
