3.1 Introduction
An effective PWM peripheral must be able to generate complex pulse width waveforms with minimal CPU
overhead or intervention. It needs to be highly programmable and very flexible while being easy to understand
and use. The ePWM unit described here addresses these requirements by allocating all needed timing and
control resources on a per PWM channel basis. Cross coupling or sharing of resources has been avoided;
instead, the ePWM is built up from smaller single channel modules with separate resources that can operate
together as required to form a system. This modular approach results in an orthogonal architecture and provides
a more transparent view of the peripheral structure, helping users to understand its operation quickly.
In this document the letter x within a signal or module name is used to indicate a generic ePWM instance
on a device. For example output signals EPWMxA and EPWMxB refer to the output signals from the ePWMx
instance. Thus, EPWM1A and EPWM1B belong to ePWM1 and likewise EPWM4A and EPWM4B belong to
ePWM4.
3.1.1 EPWM Related Collateral
Foundational Materials
•
Real-Time Control Reference Guide
– Refer to the EPWM section
Getting Started Materials
•
Flexible PWMs Enable Multi-Axis Drives, Multi-Level Inverters Application Report
•
Getting Started with the C2000 ePWM Module
(Video)
•
– Chapters 1 to 6 are Fundamental material, derivations, and explanations that are useful for learning
about how PWM can be used to implement a DAC. Subsequent chapters are Getting Started and Expert
material for implementing in a system.
•
Using the Enhanced Pulse Width Modulator (ePWM) Module Application Report
Expert Materials
•
C2000 real-time microcontrollers - Reference designs
– See TI designs related to specific end applications used.
3.1.2 Submodule Overview
The ePWM module represents one complete PWM channel composed of two PWM outputs: EPWMxA and
EPWMxB. Multiple ePWM modules are instanced within a device as shown in
is identical with one exception. Some instances include a hardware extension that allows more precise control
of the PWM outputs. This extension is the high-resolution pulse width modulator (HRPWM) and is described in
. See your device-specific data sheet to determine which ePWM instances include this feature. Each
ePWM module is indicated by a numerical value starting with 1. For example, ePWM1 is the first instance and
ePWM3 is the third instance in the system and ePWMx indicates any instance.
The ePWM modules are chained together via a clock synchronization scheme that allows them to operate
as a single system when required. Additionally, this synchronization scheme can be extended to the capture
peripheral modules (eCAP). The number of modules is device-dependent and based on target application
needs. Modules can also operate stand-alone.
Each ePWM module supports the following features:
• Dedicated 16-bit time-base counter with period and frequency control.
• Two PWM outputs (EPWMxA and EPWMxB) that can be used in the following configurations:
– Two independent PWM outputs with single-edge operation
– Two independent PWM outputs with dual-edge symmetric operation
– One independent PWM output with dual-edge asymmetric operation
Enhanced Pulse Width Modulator (ePWM) Module
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TMS320x2806x Microcontrollers
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
Copyright © 2022 Texas Instruments Incorporated
Summary of Contents for TMS320 2806 Series
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