PXD10RM Datasheet, PDF (1129/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

Chapter 35
Stepper Motor Controller (SMC)
35.1 Introduction
The SMC block is a PWM motor controller suitable for driving small stepper and air core motors used in
instrumentation applications. The module can also be used for other motor control or PWM applications
that match the frequency, resolution and output drive capabilities of the module. The SMC has 12 PWM
channels associated with two pins each (24 pins in total).
35.1.1 Features
The SMC includes the following features:
• 10/11-bit PWM counter
• 11-bit resolution with selectable PWM dithering function
• Left, right, or center aligned PWM
• Short-circuit detection in each PWM channel with programmable time-out
35.1.2 Modes of operation
35.1.2.1 Functional modes
35.1.2.1.1 Dither Function
Dither function can be selected or deselected by setting or clearing the MCCTL0[DITH] bit. This bit
influences all PWM channels. For details, please refer to Section 35.4.1.3.5, Dither Bit
(MCCTL0[DITH]).
35.1.2.2 PWM Channel Configuration Modes
The 12 PWM channels can operate in three functional modes. Those modes are, with some restrictions,
selectable for each channel independently.
35.1.2.2.1 Dual Full H-Bridge Mode
This mode is suitable to drive a stepper motor or a 360^o air gauge instrument. For details, please refer to
Section 35.4.1.1.1, Dual Full H-Bridge Mode”. In this mode two adjacent PWM channels are combined,
and two PWM channels drive four pins.
35.1.2.2.2 Full H-Bridge Mode
This mode is suitable to drive any load requiring a PWM signal in a H-bridge configuration using two pins.
For details please refer to Section 35.4.1.1.2, Full H-Bridge Mode”.
Freescale Semiconductor
PXD10 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
35-1