Stepper Motor (SM) eTPU Function

The SM function provides the eTPU with the capability of driving two-phase or three-phase stepper motors in full-step or half-step modes. The eTPU can accelerate the motors, run them at constant speed (or slew), and decelerate the motor independently of the device's CPU. The CPU need only initialize the function once, and then supply a desired position each time a move is required. The acceleration/deceleration profile is freely configured by the user via a table of step rates.

The SM eTPU function is based on the table stepper motor (TSM) TPU function. The SM eTPU function expands the TSM TPU functionality in the following items:

• Support of 3-phase motors
• Acceleration table size is unlimited (limited only by the amount of available memory)
• 16-bit acceleration ratios
• 24-bit position values (current position and desired position)

For full description refer to AN2869.