TMS320F28377D: TMS320F28377D - Best method to open all switches (High-Z) during coasting mode in motor control

Part Number: TMS320F28377D

I am implementing a sensorless PMSM drive for railway traction application using TMS320F28377D.

During the coasting section, I need to open all inverter switches and disable all gate signals, then resume PWM afterward repeatedly.

I have two questions:

1. To open all inverter switches during the coasting section, I am considering two methods:
   • Method 1: Force all PWM outputs to low using AQCSFRC
   • Method 2: Disable the dead band and apply individual signals to each switch directly
   Are these the correct and recommended approaches? Or is there another method I should consider?
2. Considering propagation delay through the gate driver, which method provides the fastest and most deterministic switch-off timing — AQCSFRC, Trip Zone (OST), or controlling the gate driver enable pin directly?

Any recommendation on the preferred approach in a safety-critical traction application would be appreciated.