SLVSD14A June 2017 – June 2020 DRV10983-Q1
The motor operation speed is automatically updated in register MotorSpeed while the motor is spinning. The value is determined by the period for calculated BEMF zero crossings on phase U. The electrical speed of the motor is denoted as Velocity (Hz) and is calculated as shown in Equation 9.
As an example consider the following:
MotorSpeed = 0x01FF;
Velocity = 512 (0x01FF) / 10 = 51 Hz
For a 4-pole motor, this translates to: