MCT8316Z: MTR_LOCK Error

Hi

We are using MCT8316Z drivers and get status bit errors - 

- the NPOR (Supply Power On Reset) is always set to '1' - I assume this means NO ERROR (opposite to all other status bits where '1' indicate failure)

-The MTR_LOCK is switching to '1' every ~300mSec, after Clear faults it's fine for anther 300mSec..

  at that time we provide Low PWM to the motor, but the motor is not moving ( no change in Hall sensors).

 the failure indication mentions "Hall signals are not present" - what does it mean ? no halls mean - no hall change ? or halls in inappropriate state (Like 0/0/0)?