Introduction
1436
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Pulse Width Modulator (PWM)
21.1 Introduction
The MSP432E4 microcontroller contains one PWM module, with four PWM generator blocks and a control
block, for a total of eight PWM outputs. The control block determines the polarity of the PWM signals, and
which signals are passed through to the pins.
Each PWM generator block produces two PWM signals that share the same timer and frequency and can
either be programmed with independent actions or as a single pair of complementary signals with dead-
band delays inserted. The output signals, pwmA' and pwmB', of the PWM generation blocks are managed
by the output control block before being passed to the device pins as MnPWM0 and MnPWM1 or
MnPWM2 and MnPWM3, and so on.
The PWM module provides a great deal of flexibility and can generate simple PWM signals, such as those
required by a simple charge pump as well as paired PWM signals with dead-band delays, such as those
required by a half-H bridge driver. Three generator blocks can also generate the full six channels of gate
controls required by a three-phase inverter bridge.
Each PWM generator block has the following features:
•
Four fault-condition handling inputs to quickly provide low-latency shutdown and prevent damage to
the motor being controlled
•
One 16-bit counter:
–
Runs in Down or Up/Down mode
–
Output frequency controlled by a 16-bit load value
–
Load value updates can be synchronized
–
Produces output signals at zero and load value
•
Two PWM comparators:
–
Comparator value updates can be synchronized
–
Produces output signals on match
•
PWM signal generator:
–
Output PWM signal is constructed based on actions taken as a result of the counter and PWM
comparator output signals
–
Produces two independent PWM signals
•
Dead-band generator:
–
Produces two PWM signals with programmable dead-band delays suitable for driving a half-H
bridge
–
Can be bypassed, leaving input PWM signals unmodified
•
Can initiate an ADC sample sequence
The control block determines the polarity of the PWM signals and which signals are passed through to the
pins. The output of the PWM generation blocks are managed by the output control block before being
passed to the device pins. The PWM control block has the following options:
•
PWM output enable of each PWM signal
•
Optional output inversion of each PWM signal (polarity control)
•
Optional fault handling for each PWM signal
•
Synchronization of timers in the PWM generator blocks
•
Synchronization of timer/comparator updates across the PWM generator blocks
•
Extended PWM synchronization of timer/comparator updates across the PWM generator blocks
•
Interrupt status summary of the PWM generator blocks
•
Extended PWM fault handling, with multiple fault signals, programmable polarities, and filtering
•
PWM generators can be operated independently or synchronized with other generators