MCF523X Datasheet, PDF (1/44 Pages) Freescale Semiconductor, Inc – DC Motor with Speed and Current Closed Loops, Driven by eTPU on

Freescale Semiconductor
Application Note
AN2955
Rev. 0, 06/2005
DC Motor with Speed and Current
Closed Loops, Driven by eTPU on
MCF523x
Covers MCF523x and all eTPU-equipped Devices
by: Milan Brejl & Michal Princ
System Application Engineers
Roznov Czech System Center
This application note describes the design of a DC motor
drive based on Freescale’s ColdFire MCF523x
microprocessor. The application design takes advantage
of the enhanced time processing unit (eTPU) module,
which is used as a motor control co-processor. The eTPU
completely handles the motor control processing,
eliminating the microprocessor overhead for other
duties.
The concept of the application is to create a speed and
current closed loop DC driver using an optical, Hall-like
position sensor. It serves as an example of a DC motor
control system design using a Freescale microprocessor
with the eTPU. It also illustrates the usage of dedicated
motor control eTPU functions that are included in the
DC motor control eTPU function set.
This application note also includes basic motor theory,
system design concept, hardware implementation, and
microprocessor and eTPU software design, including the
FreeMASTER visualization tool.
Table of Contents
1 ColdFire MCF523x and eTPU Advantages and
Features ..............................................................2
2 Target Motor Theory ............................................4
3 System Concept ..................................................6
4 Software Design ................................................15
5 Implementation Notes .......................................38
6 Microprocessor Usage ......................................39
7 Summary and Conclusions ...............................40
8 References ........................................................41
© Freescale Semiconductor, Inc., 2005. All rights reserved.