Texas Instruments 28xxx User Manual

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PIE
Event Trigger
Module Logic
CTR=Zero
CTR=PRD
CTR=CMPA
EPWMxINTn
CTR=CMPB
CTR_dir
Direction
qualifier
CTRU=CMPA
ETSEL reg
EPWMxSOCA
/n
/n
/n
EPWMxSOCB
ADC
clear
count
count
clear
count
clear
CTRD=CMPA
CTRU=CMPB
CTRD=CMPB
ETPS reg
ETFLG reg
ETCLR reg
ETFRC reg
Event-Trigger (ET) Submodule
Figure 2-40. Event-Trigger Submodule Showing Event Inputs and Prescaled Outputs
The key registers used to configure the event-trigger submodule are shown in Table 2-19 :
Table 2-19. Event-Trigger Submodule Registers
Register Name Address offset Shadowed Description
ETSEL 0x0019 No Event-trigger Selection Register
ETPS 0x001A No Event-trigger Prescale Register
ETFLG 0x001B No Event-trigger Flag Register
ETCLR 0x001C No Event-trigger Clear Register
ETFRC 0x001D No Event-trigger Force Register
• ETSEL—This selects which of the possible events will trigger an interrupt or start an ADC conversion
• ETPS—This programs the event prescaling options mentioned above.
• ETFLG—These are flag bits indicating status of the selected and prescaled events.
• ETCLR—These bits allow you to clear the flag bits in the ETFLG register via software.
• ETFRC—These bits allow software forcing of an event. Useful for debugging or s/w intervention.
A more detailed look at how the various register bits interact with the Interrupt and ADC start of
conversion logic are shown in Figure 2-41 , Figure 2-42 , and Figure 2-43 .
Figure 2-41 shows the event-trigger's interrupt generation logic. The interrupt-period (ETPS[INTPRD]) bits
specify the number of events required to cause an interrupt pulse to be generated. The choices available
are:
• Do not generate an interrupt.
• Generate an interrupt on every event
• Generate an interrupt on every second event
• Generate an interrupt on every very third event
Which event can cause an interrupt is configured by the interrupt selection (ETSEL[INTSEL]) bits. The
event can be one of the following:
• Time-base counter equal to zero (TBCTR = 0x0000).
• Time-base counter equal to period (TBCTR = TBPRD).
• Time-base counter equal to the compare A register (CMPA) when the timer is incrementing.
• Time-base counter equal to the compare A register (CMPA) when the timer is decrementing.
• Time-base counter equal to the compare B register (CMPB) when the timer is incrementing.
• Time-base counter equal to the compare B register (CMPB) when the timer is decrementing.
SPRU791D – November 2004 – Revised October 2007 ePWM Submodules 65
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Texas Instruments 28xxx Specifications

General

Brand	Texas Instruments
Model	28xxx
Category	Accessories
Language	English

Summary

Preface

Read This First

Important introductory information and related documentation.

Introduction

1.1 Introduction

Overview of the ePWM peripheral's design and programmability.

1.2 Submodule Overview

Details the seven submodules that compose an ePWM module and their interconnections.

1.3 Register Mapping

Explains how ePWM module control and status registers are grouped by submodule.

ePWM Submodules

2.1 Overview

Lists the seven key ePWM submodules and their main configuration parameters.

2.2 Time-Base (TB) Submodule

Explains the time-base submodule's role in event timing and synchronization for ePWM modules.

2.3 Counter-Compare (CC) Submodule

Describes the counter-compare submodule's function in generating events based on time-base counter values.

2.4 Action-Qualifier (AQ) Submodule

Explains the action-qualifier's role in waveform construction and PWM generation.

2.5 Dead-Band Generator (DB) Submodule

Explains the dead-band submodule's function in generating signal pairs with dead-band relationships.

2.6 PWM-Chopper (PC) Submodule

Explains the PWM-chopper submodule's role in modulating PWM waveforms with a high-frequency carrier.

2.7 Trip-Zone (TZ) Submodule

Explains the trip-zone submodule's function for detecting external fault conditions and responding to them.

2.8 Event-Trigger (ET) Submodule

Describes the event-trigger submodule's functions for managing interrupts and ADC conversions.

Dead-Band Generator (DB) Submodule

2.5.1 Purpose of the Dead-Band Submodule

Explains the dead-band submodule's function in generating signal pairs with dead-band relationships.

2.5.2 Controlling and Monitoring the Dead-Band Submodule

Details the registers used to control and monitor the dead-band generator submodule.

2.5.3 Operational Highlights for the Dead-Band Submodule

Provides operational highlights for the dead-band submodule, including input source and output modes.

PWM-Chopper (PC) Submodule

2.6.1 Purpose of the PWM-Chopper Submodule

Explains the PWM-chopper submodule's role in modulating PWM waveforms with a high-frequency carrier.

2.6.2 Controlling the PWM-Chopper Submodule

Details the registers used to control the PWM-chopper submodule.

2.6.3 Operational Highlights for the PWM-Chopper Submodule

Highlights operational details of the PWM-chopper submodule, including carrier clock and one-shot features.

2.6.4 Waveforms

Shows simplified waveforms illustrating the PWM-chopper's chopping action.

Trip-Zone (TZ) Submodule

2.7.1 Purpose of the Trip-Zone Submodule

Explains the trip-zone submodule's function for detecting external fault conditions and responding to them.

2.7.2 Controlling and Monitoring the Trip-Zone Submodule

Details the registers used to control and monitor the trip-zone submodule.

2.7.3 Operational Highlights for the Trip-Zone Submodule

Describes operational highlights and configuration options for the trip-zone submodule.

2.7.4 Generating Trip Event Interrupts

Illustrates the trip-zone submodule's control and interrupt logic.

Applications to Power Topologies

3.1 Overview of Multiple Modules

Provides an overview of how multiple ePWM modules work together in a system.

3.2 Key Configuration Capabilities

Lists key configuration choices available for ePWM modules when used in multi-module systems.

3.3 Controlling Multiple Buck Converters With Independent Frequencies

Explains how to control multiple buck converters with independent PWM frequencies using ePWM modules.

3.4 Controlling Multiple Buck Converters With Same Frequencies

Explains how to control multiple buck converters with the same PWM frequency using synchronized ePWM modules.

3.5 Controlling Multiple Half H-Bridge (HHB) Converters

Describes controlling multiple Half-H bridge converters using ePWM modules.

3.6 Controlling Dual 3-Phase Inverters for Motors (ACI and PMSM)

Details controlling dual 3-phase inverters for motor control using ePWM modules.

3.7 Practical Applications Using Phase Control Between PWM Modules

Demonstrates using phase control between PWM modules for power topologies.

3.8 Controlling a 3-Phase Interleaved DC/DC Converter

Explains controlling a 3-phase interleaved DC/DC converter using phase-offset PWM modules.

3.9 Controlling Zero Voltage Switched Full Bridge (ZVSFB) Converter

Describes controlling a Zero Voltage Switched Full Bridge (ZVSFB) converter using ePWM modules.

Registers

4.1 Time-Base Submodule Registers

Describes the registers associated with the Time-Base (TB) submodule.

4.2 Counter-Compare Submodule Registers

Describes the registers associated with the Counter-Compare (CC) submodule.

4.3 Action-Qualifier Submodule Registers

Describes the registers associated with the Action-Qualifier (AQ) submodule.

4.4 Dead-Band Submodule Registers

Describes the registers associated with the Dead-Band Generator (DB) submodule.

4.5 PWM-Chopper Submodule Control Register

Details the control register for the PWM-Chopper (PC) submodule.

4.6 Trip-Zone Submodule Control and Status Registers

Describes the control and status registers for the Trip-Zone (TZ) submodule.

4.7 Event-Trigger Submodule Registers

Describes the registers used to configure and control the Event-Trigger (ET) submodule.

4.8 Proper Interrupt Initialization Procedure

Outlines the correct procedure for initializing ePWM peripheral interrupts to avoid spurious events.

Revision History

Table A-1. Changes for Revision D

Details modifications, additions, and deletions for revision D.