TMS320F28377D: The question about ISR frequency and PWM frequency in using SFRA

3-phase  rectifier, the main ISR is 16kHz, and the PWM frequency is 8k, update twice comparator value in a PWM period.

So, the SFRA_ISR_FREQ value is 16k or 8k?

I don't know which is correct, cause there is a big different between 16k and 8k from the bode result.

Thanks a lot guys...