Texas Instruments TMS320x28xx, 28xxx manual Overview, Submodule Configuration Parameters

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Overview

2.1Overview

Table 2-1lists the seven key submodules together with a list of their main configuration parameters. For example, if you need to adjust or control the duty cycle of a PWM waveform, then you should see the counter-compare submodule in Section 2.3 for relevant details.

 

 

Table 2-1. Submodule Configuration Parameters

Submodule

Configuration Parameter or Option

Time-base (TB)

∙

Scale the time-base clock (TBCLK) relative to the system clock (SYSCLKOUT).

 

∙

Configure the PWM time-base counter (TBCTR) frequency or period.

 

∙

Set the mode for the time-base counter:

 

 

– count-up mode: used for asymmetric PWM

 

 

– count-down mode: used for asymmetric PWM

 

 

– count-up-and-down mode: used for symmetric PWM

 

∙

Configure the time-base phase relative to another ePWM module.

 

∙

Synchronize the time-base counter between modules through hardware or software.

 

∙

Configure the direction (up or down) of the time-base counter after a synchronization event.

 

∙

Configure how the time-base counter will behave when the device is halted by an emulator.

 

∙

Specify the source for the synchronization output of the ePWM module:

 

 

–

Synchronization input signal

 

 

– Time-base counter equal to zero

 

 

– Time-base counter equal to counter-compare B (CMPB)

 

 

– No output synchronization signal generated.

Counter-compare (CC)

∙

Specify the PWM duty cycle for output EPWMxA and/or output EPWMxB

 

∙

Specify the time at which switching events occur on the EPWMxA or EPWMxB output

Action-qualifier (AQ)

∙

Specify the type of action taken when a time-base or counter-compare submodule event occurs:

 

 

–

No action taken

 

 

– Output EPWMxA and/or EPWMxB switched high

 

 

– Output EPWMxA and/or EPWMxB switched low

 

 

– Output EPWMxA and/or EPWMxB toggled

 

∙

Force the PWM output state through software control

 

∙

Configure and control the PWM dead-band through software

Dead-band (DB)

∙

Control of traditional complementary dead-band relationship between upper and lower switches

 

∙

Specify the output rising-edge-delay value

 

∙

Specify the output falling-edge delay value

 

∙

Bypass the dead-band module entirely. In this case the PWM waveform is passed through

 

 

without modification.

PWM-chopper (PC)

∙

Create a chopping (carrier) frequency.

 

∙

Pulse width of the first pulse in the chopped pulse train.

 

∙

Duty cycle of the second and subsequent pulses.

 

∙

Bypass the PWM-chopper module entirely. In this case the PWM waveform is passed through

 

 

without modification.

Trip-zone (TZ)

∙

Configure the ePWM module to react to one, all, or none of the trip-zone pins.

 

∙

Specify the tripping action taken when a fault occurs:

 

 

– Force EPWMxA and/or EPWMxB high

 

 

– Force EPWMxA and/or EPWMxB low

 

 

– Force EPWMxA and/or EPWMxB to a high-impedance state

 

 

– Configure EPWMxA and/or EPWMxB to ignore any trip condition.

 

∙

Configure how often the ePWM will react to each trip-zone pin:

 

 

–

One-shot

 

 

– Cycle-by-cycle

 

∙

Enable the trip-zone to initiate an interrupt.

 

∙

Bypass the trip-zone module entirely.

20

ePWM Submodules

SPRU791D–November 2004–Revised October 2007

 

 

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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 Related Documentation From Texas Instruments Data ManualsCPU Users Guides Peripheral GuidesTools Guides Application ReportsTrademarks TMS320C28x, C28x are trademarks of Texas InstrumentsSubmit Documentation Feedback Introduction Introduction Submodule OverviewMultiple ePWM Modules ∙ PWM output signals EPWMxA and EPWMxB ∙ Trip-zone signals TZ1 to TZ6∙ ADC start-of-conversion signals EPWMxSOCA and EPWMxSOCB ∙ Peripheral BusEPWM Submodules and Critical Internal Signal Interconnects Register MappingOffset Size Name DescriptionTime-Base Submodule Registers Counter-Compare Submodule RegistersEPWM Submodules Overview Submodule Configuration ParametersSubmodule Configuration Parameter or Option Example 2-1. Constant Definitions Used in the Code Examples TbupChpenable Time-Base TB Submodule Purpose of the Time-Base SubmoduleRegister Controlling and Monitoring the Time-base SubmoduleTime-Base Submodule Registers Key Time-Base Signals ∙ Up-Down-Count Mode∙ Up-Count Mode ∙ Down-Count Mode∙ Time-Base Period Shadow Mode ∙ Time-Base Period Immediate Load ModeTime-Base Period Shadow Register ∙ Active RegisterTime-Base Counter Synchronization Time-Base Counter Synchronization SchemeEPWM11SYNCI EPWM11SYNCO∙ EPWMxSYNCI Synchronization Input Pulse ∙ Software Forced Synchronization PulsePhase Locking the Time-Base Clocks of Multiple ePWM Modules Time-base Counter Modes and Timing WaveformsTime-Base Down-Count Mode Waveforms Counter-Compare CC Submodule 11. Counter-Compare SubmodulePurpose of the Counter-Compare Submodule Controlling and Monitoring the Counter-Compare SubmoduleCounter-Compare Submodule Registers Register Name Address OffsetCount Mode Timing Waveforms Counter-Compare Submodule Key Signals∙ Shadow Mode ∙ Immediate Load ModeCTR=CMPA CTR=CMPBCTR = Cmpb Action-Qualifier Submodule Registers Action-Qualifier AQ SubmodulePurpose of the Action-Qualifier Submodule Action-Qualifier Submodule Possible Input Events ∙ Set High∙ Clear Low ∙ ToggleTB Counter equals Actions Action-Qualifier Event Priority for Up-Down-Count Mode Action-Qualifier Event Priority for Up-Count Mode10. Action-Qualifier Event Priority for Down-Count Mode Action-Qualifier Event PriorityWaveforms for Common Configurations Use up-down-count mode to generate a symmetric PWMUse up-down-count mode to generate an asymmetric PWM When using up-count mode to generate an asymmetric PWM20. Up-Down-Count Mode Symmetrical Waveform Example 2-2. Code Sample for Figure TbctrValue EPWMxA EPWMxB Example 2-3. Code Sample for Figure Tbclk = SysclkoutExample 2-4. Code Sample for Figure EdgePosAExample 2-5. Code Sample for Figure Example 2-6. Code Sample for Figure TbctrExample 2-7. Code Sample for Figure EPWMxA EPWMxBDead-Band Generator DB Submodule Purpose of the Dead-Band SubmoduleControlling and Monitoring the Dead-Band Submodule 12. Dead-Band Generator Submodule Registers∙ Output Mode Control Operational Highlights for the Dead-Band Submodule∙ Input Source Selection ∙ Polarity ControlMode Description 13. Classical Dead-Band Operating Modes29. Dead-Band Waveforms for Typical Cases 0% Duty 100% Dead-Band Delay in μS FED = Dbfed × Ttbclk RED = Dbred × TtbclkPWM-Chopper PC Submodule Purpose of the PWM-Chopper SubmoduleControlling the PWM-Chopper Submodule Operational Highlights for the PWM-Chopper SubmoduleWaveforms 31. PWM-Chopper Submodule Operational DetailsOSHTWTHz One-Shot Pulse16. Possible Pulse Width Values for Sysclkout = 100 MHz Duty Cycle Control PeriodTrip-Zone TZ Submodule Purpose of the Trip-Zone SubmoduleControlling and Monitoring the Trip-Zone Submodule Operational Highlights for the Trip-Zone Submodule17. Trip-Zone Submodule Registers ∙ Cycle-by-Cycle CBCExample 2-8. Trip-Zone Configurations 18. Possible Actions On a Trip EventScenario a Scenario B36. Trip-Zone Submodule Mode Control Logic Generating Trip Event InterruptsEvent-Trigger ET Submodule 37. Trip-Zone Submodule Interrupt LogicOperational Overview of the Event-Trigger Submodule 19. Event-Trigger Submodule Registers CTR=CMPB CTRD=CMPB41. Event-Trigger Interrupt Generator 42. Event-Trigger Soca Pulse Generator Submit Documentation Feedback Applications to Power Topologies Controlling Multiple Buck Converters With IndependentKey Configuration Capabilities Overview of Multiple ModulesCTR=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 500Controlling Multiple Buck Converters With Same Frequencies Control of Four Buck Stages. Note FPWM2 = N x FPWM1Buck 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 FPWM1Half-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 FigureEPWM1A 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 Converter13. 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 Trip-Zone Submodule Control and Status Registers Proper Interrupt Initialization ProcedurePWM-Chopper Submodule Control Register Time-Base Phase Register Tbphs Field Descriptions Time-Base Submodule RegistersTime-Base Period Register Tbprd Field Descriptions Time-Base Counter Register Tbctr Field DescriptionsTime-Base Control Register Tbctl Field Descriptions Bit Field Value DescriptionSoftware Forced Synchronization Pulse Bit Field Counter-Compare Submodule RegistersTime-Base Status Register Tbsts Field Descriptions Bits Name Description Counter-Compare a Register Cmpa Field DescriptionsCounter-Compare B Register Cmpb Field Descriptions Action-Qualifier Submodule Registers Counter-Compare Control Register Cmpctl Field DescriptionsCBD CBD CBU CAD CAU PRD ZROBits Name 10. Action-Qualifier Output B Control Register Aqctlb Csfb Csfa Rldcsf Otsfb Actsfb Otsfa ActsfaRldcsf Inmode Polsel Outmode Dead-Band Submodule RegistersCsfb Inmode PWM-Chopper Submodule Control Register 16. PWM-Chopper Control Register Pcctl Bit DescriptionsName Value Description ReservedChpduty Trip-Zone Submodule Control and Status RegistersPWM-Chopper Control Register Pcctl Bit Descriptions OSHT6 OSHT5 OSHT4 OSHT3 OSHT2 OSHT1 CBC6 CBC5 CBC4 CBC3 CBC2 CBC1OSHT6 CBC618. Trip-Zone Control Register Tzctl Field Descriptions TZB TZATZB OST CBC20. Trip-Zone Flag Register Tzflg Field Descriptions OST CBC INT22. Trip-Zone Force Register Tzfrc Field Descriptions Event-Trigger Submodule Registers21. Trip-Zone Clear Register Tzclr Field Descriptions 23. Event-Trigger Selection Register Etsel 24. Event-Trigger Prescale Register Etps Field Descriptions Name Description24. Event-Trigger Prescale Register Etps Field Descriptions Socb SocaSocb 25. Event-Trigger Flag Register Etflg Field Descriptions26. Event-Trigger Clear Register Etclr Field Descriptions Proper Interrupt Initialization Procedure 27. Event-Trigger Force Register Etfrc Field Descriptions116 Table A-1. Changes for Revision D Location Modifications, Additions, and DeletionsAppendix a Important Notice
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