DRV8353: SHx pins can not be HiZ in 1xPWM mode

Hi 

We designed a motor drive circuit with drv8353s.

1xPWM mode is used for motor driving.

When DRV is disable(sleep mode), motor can be spined easy by hand.

However when DRV is enable(active) and the referance PWM signal is not be implemented to DRV,  motor is aligned and spinning the motor is more difficult.

We checked SHx pins. SHx pins are connected to GND. According to datasheet  SHx pins must be HiZ or  Not Connected. 

How can we get SHx pins as NOT CONNECTED?