Overview of Multiple Modules | Texas Instruments TMS320x28xx, 28xxx

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Overview of Multiple Modules

3.1Overview of Multiple Modules

Previously in this user's guide, all discussions have described the operation of a single module. To facilitate the understanding of multiple modules working together in a system, the ePWM module described in reference is represented by the more simplified block diagram shown in Figure 3-1. This simplified ePWM block shows only the key resources needed to explain how a multiswitch power topology is controlled with multiple ePWM modules working together.

Figure 3-1. Simplified ePWM Module

	Phase reg	SyncIn
	Phase reg	EN
		EN
	Φ=0°
	CTR = 0
	CTR=CMPB
		X
		SyncOut

EPWMxA

EPWMxB

3.2Key Configuration Capabilities

The key configuration choices available to each module are as follows:

∙Options for SyncIn

–Load own counter with phase register on an incoming sync strobe—enable (EN) switch closed

–Do nothing or ignore incoming sync strobe—enable switch open

–Sync flow-through - SyncOut connected to SyncIn

–Master mode, provides a sync at PWM boundaries—SyncOut connected to CTR = PRD

–Master mode, provides a sync at any programmable point in time—SyncOut connected to CTR =

CMPB

–Module is in standalone mode and provides No sync to other modules—SyncOut connected to X (disabled)

∙Options for SyncOut

–Sync flow-through - SyncOut connected to SyncIn

–Master mode, provides a sync at PWM boundaries—SyncOut connected to CTR = PRD

–Master mode, provides a sync at any programmable point in time—SyncOut connected to CTR =

CMPB

–Module is in standalone mode and provides No sync to other modules—SyncOut connected to X (disabled)

For each choice of SyncOut, a module may also choose to load its own counter with a new phase value on a SyncIn strobe input or choose to ignore it, i.e., via the enable switch. Although various combinations are possible, the two most common—master module and slave module modes—are shown in Figure 3-2.

70

Applications to Power Topologies

SPRU791D–November 2004–Revised October 2007

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Texas Instruments TMS320x28xx, 28xxx manual Overview of Multiple Modules, Key Configuration Capabilities

Contents

Reference Guide Submit Documentation Feedback Contents Controlling a 3-Phase Interleaved DC/DC Converter List of Figures Event-Trigger Socb Pulse Generator Simplified ePWM Module List of Tables Submit Documentation Feedback CPU Users Guides Related Documentation From Texas InstrumentsData Manuals Peripheral Guides Tools Guides Application Reports Trademarks TMS320C28x, C28x are trademarks of Texas Instruments Submit Documentation Feedback Introduction Introduction Submodule Overview Multiple ePWM Modules ∙ ADC start-of-conversion signals EPWMxSOCA and EPWMxSOCB ∙ PWM output signals EPWMxA and EPWMxB∙ Trip-zone signals TZ1 to TZ6 ∙ Peripheral Bus EPWM Submodules and Critical Internal Signal Interconnects Register Mapping Time-Base Submodule Registers Offset Size NameDescription Counter-Compare Submodule Registers EPWM Submodules Submodule Configuration Parameter or Option Submodule Configuration ParametersOverview Example 2-1. Constant Definitions Used in the Code Examples Tbup Chpenable Time-Base TB Submodule Purpose of the Time-Base Submodule Time-Base Submodule Registers Controlling and Monitoring the Time-base SubmoduleRegister ∙ Up-Count Mode Key Time-Base Signals∙ Up-Down-Count Mode ∙ Down-Count Mode Time-Base Period Shadow Register ∙ Time-Base Period Shadow Mode∙ Time-Base Period Immediate Load Mode ∙ Active Register Time-Base Counter Synchronization Time-Base Counter Synchronization Scheme EPWM11SYNCI EPWM11SYNCO ∙ EPWMxSYNCI Synchronization Input Pulse ∙ Software Forced Synchronization Pulse Phase Locking the Time-Base Clocks of Multiple ePWM Modules Time-base Counter Modes and Timing Waveforms Time-Base Down-Count Mode Waveforms Counter-Compare CC Submodule 11. Counter-Compare Submodule Counter-Compare Submodule Registers Purpose of the Counter-Compare SubmoduleControlling and Monitoring the Counter-Compare Submodule Register Name Address Offset ∙ Shadow Mode Count Mode Timing WaveformsCounter-Compare Submodule Key Signals ∙ Immediate Load Mode CTR=CMPA CTR=CMPB CTR = Cmpb Purpose of the Action-Qualifier Submodule Action-Qualifier AQ SubmoduleAction-Qualifier Submodule Registers ∙ Clear Low Action-Qualifier Submodule Possible Input Events∙ Set High ∙ Toggle TB Counter equals Actions 10. Action-Qualifier Event Priority for Down-Count Mode Action-Qualifier Event Priority for Up-Down-Count ModeAction-Qualifier Event Priority for Up-Count Mode Action-Qualifier Event Priority Use up-down-count mode to generate an asymmetric PWM Waveforms for Common ConfigurationsUse up-down-count mode to generate a symmetric PWM When using up-count mode to generate an asymmetric PWM 20. Up-Down-Count Mode Symmetrical Waveform Example 2-2. Code Sample for Figure Tbctr Value EPWMxA EPWMxB Example 2-3. Code Sample for Figure Tbclk = Sysclkout Example 2-4. Code Sample for Figure EdgePosA Example 2-5. Code Sample for Figure Example 2-6. Code Sample for Figure Tbctr Example 2-7. Code Sample for Figure EPWMxA EPWMxB Controlling and Monitoring the Dead-Band Submodule Dead-Band Generator DB SubmodulePurpose of the Dead-Band Submodule 12. Dead-Band Generator Submodule Registers ∙ Input Source Selection ∙ Output Mode ControlOperational Highlights for the Dead-Band Submodule ∙ Polarity Control Mode Description 13. Classical Dead-Band Operating Modes 29. Dead-Band Waveforms for Typical Cases 0% Duty 100% Dead-Band Delay in μS FED = Dbfed × Ttbclk RED = Dbred × Ttbclk Controlling the PWM-Chopper Submodule PWM-Chopper PC SubmodulePurpose of the PWM-Chopper Submodule Operational Highlights for the PWM-Chopper Submodule Waveforms 31. PWM-Chopper Submodule Operational Details 16. Possible Pulse Width Values for Sysclkout = 100 MHz One-Shot PulseOSHTWTHz Duty Cycle Control Period Trip-Zone TZ Submodule Purpose of the Trip-Zone Submodule 17. Trip-Zone Submodule Registers Controlling and Monitoring the Trip-Zone SubmoduleOperational Highlights for the Trip-Zone Submodule ∙ Cycle-by-Cycle CBC Scenario a Example 2-8. Trip-Zone Configurations18. Possible Actions On a Trip Event Scenario B 36. Trip-Zone Submodule Mode Control Logic Generating Trip Event Interrupts Event-Trigger ET Submodule 37. Trip-Zone Submodule Interrupt Logic Operational Overview of the Event-Trigger Submodule 19. Event-Trigger Submodule Registers CTR=CMPB CTRD=CMPB 41. Event-Trigger Interrupt Generator 42. Event-Trigger Soca Pulse Generator Submit Documentation Feedback Applications to Power Topologies Controlling Multiple Buck Converters With Independent Key Configuration Capabilities Overview of Multiple Modules CTR=0 EPWM1B CTR=CMPB Control of Four Buck Stages. Here FPWM1≠ FPWM2≠ FPWM3≠ FPWM4 Buck Waveforms for -3Note Only three bucks shown here Example 3-1. Configuration for Example in Figure 500 Controlling Multiple Buck Converters With Same Frequencies Control of Four Buck Stages. Note FPWM2 = N x FPWM1 Buck Waveforms for -5Note FPWM2 = FPWM1 Example 3-2. Code Snippet for Configuration in Figure Controlling Multiple Half H-Bridge HHB Converters Control of Two Half-H Bridge Stages FPWM2 = N x FPWM1 Half-H Bridge Waveforms for -7Note Here FPWM2 = FPWM1 Controlling Dual 3-Phase Inverters for Motors ACI and Pmsm Example 3-3. Code Snippet for Configuration in Figure EPWM1A 10 -Phase Inverter Waveforms for -9Only One Inverter Shown Example 3-4. Code Snippet for Configuration in Figure 11. Configuring Two PWM Modules for Phase Control Controlling a 3-Phase Interleaved DC/DC Converter Controlling a 3-Phase Interleaved DC/DC Converter 13. Control of a 3-Phase Interleaved DC/DC Converter 14 -Phase Interleaved DC/DC Converter Waveforms for Figure Example 3-5. Code Snippet for Configuration in Figure 15. Controlling a Full-H Bridge Stage FPWM2 = FPWM1 16. ZVS Full-H Bridge Waveforms Example 3-6. Code Snippet for Configuration in Figure Submit Documentation Feedback PWM-Chopper Submodule Control Register Proper Interrupt Initialization ProcedureTrip-Zone Submodule Control and Status Registers Time-Base Period Register Tbprd Field Descriptions Time-Base Phase Register Tbphs Field DescriptionsTime-Base Submodule Registers Time-Base Counter Register Tbctr Field Descriptions Time-Base Control Register Tbctl Field Descriptions Bit Field Value Description Software Forced Synchronization Pulse Time-Base Status Register Tbsts Field Descriptions Counter-Compare Submodule RegistersBit Field Counter-Compare B Register Cmpb Field Descriptions Counter-Compare a Register Cmpa Field DescriptionsBits Name Description Action-Qualifier Submodule Registers Counter-Compare Control Register Cmpctl Field Descriptions Bits Name CBD CBU CAD CAU PRD ZROCBD 10. Action-Qualifier Output B Control Register Aqctlb Rldcsf Rldcsf Otsfb Actsfb Otsfa ActsfaCsfb Csfa Csfb Dead-Band Submodule RegistersInmode Polsel Outmode Inmode Name Value Description PWM-Chopper Submodule Control Register16. PWM-Chopper Control Register Pcctl Bit Descriptions Reserved PWM-Chopper Control Register Pcctl Bit Descriptions Trip-Zone Submodule Control and Status RegistersChpduty OSHT6 OSHT6 OSHT5 OSHT4 OSHT3 OSHT2 OSHT1CBC6 CBC5 CBC4 CBC3 CBC2 CBC1 CBC6 TZB 18. Trip-Zone Control Register Tzctl Field DescriptionsTZB TZA OST CBC 20. Trip-Zone Flag Register Tzflg Field Descriptions OST CBC INT 21. Trip-Zone Clear Register Tzclr Field Descriptions Event-Trigger Submodule Registers22. Trip-Zone Force Register Tzfrc Field Descriptions 23. Event-Trigger Selection Register Etsel 24. Event-Trigger Prescale Register Etps Field Descriptions Name Description 24. Event-Trigger Prescale Register Etps Field Descriptions Socb Soca 26. Event-Trigger Clear Register Etclr Field Descriptions 25. Event-Trigger Flag Register Etflg Field DescriptionsSocb Proper Interrupt Initialization Procedure 27. Event-Trigger Force Register Etfrc Field Descriptions 116 Table A-1. Changes for Revision D Location Modifications, Additions, and Deletions Appendix a Important Notice