Texas Instruments TMS320x28xx, 28xxx manual Counter-Compare a Register Cmpa Field Descriptions

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Counter-Compare Submodule Registers

		Table 4-6. Counter-Compare A Register (CMPA) Field Descriptions
Bits	Name	Description
15-0	CMPA	The value in the active CMPA register is continuously compared to the time-base counter (TBCTR). When
		the values are equal, the counter-compare module generates a "time-base counter equal to counter
		compare A" event. This event is sent to the action-qualifier where it is qualified and converted it into one
		or more actions. These actions can be applied to either the EPWMxA or the EPWMxB output depending
		on the configuration of the AQCTLA and AQCTLB registers. The actions that can be defined in the
		AQCTLA and AQCTLB registers include:
		∙	Do nothing; the event is ignored.
		∙	Clear: Pull the EPWMxA and/or EPWMxB signal low
		∙	Set: Pull the EPWMxA and/or EPWMxB signal high
		∙	Toggle the EPWMxA and/or EPWMxB signal

Shadowing of this register is enabled and disabled by the CMPCTL[SHDWAMODE] bit. By default this register is shadowed.

∙If CMPCTL[SHDWAMODE] = 0, then the shadow is enabled and any write or read will automatically go to the shadow register. In this case, the CMPCTL[LOADAMODE] bit field determines which event will load the active register from the shadow register.

∙Before a write, the CMPCTL[SHDWAFULL] bit can be read to determine if the shadow register is currently full.

∙If CMPCTL[SHDWAMODE] = 1, then the shadow register is disabled and any write or read will go directly to the active register, that is the register actively controlling the hardware.

∙In either mode, the active and shadow registers share the same memory map address.

Figure 4-7. Counter-Compare B Register (CMPB)

15

0

CMPB

R/W-0

LEGEND: R/W = Read/Write; R = Read only; -n = value after reset

		Table 4-7. Counter-Compare B Register (CMPB) Field Descriptions
Bits	Name	Description
15-0	CMPB	The value in the active CMPB register is continuously compared to the time-base counter (TBCTR). When
		the values are equal, the counter-compare module generates a "time-base counter equal to counter
		compare B" event. This event is sent to the action-qualifier where it is qualified and converted it into one
		or more actions. These actions can be applied to either the EPWMxA or the EPWMxB output depending
		on the configuration of the AQCTLA and AQCTLB registers. The actions that can be defined in the
		AQCTLA and AQCTLB registers include:
		∙	Do nothing. event is ignored.
		∙	Clear: Pull the EPWMxA and/or EPWMxB signal low
		∙	Set: Pull the EPWMxA and/or EPWMxB signal high
		∙	Toggle the EPWMxA and/or EPWMxB signal

Shadowing of this register is enabled and disabled by the CMPCTL[SHDWBMODE] bit. By default this register is shadowed.

∙If CMPCTL[SHDWBMODE] = 0, then the shadow is enabled and any write or read will automatically go to the shadow register. In this case, the CMPCTL[LOADBMODE] bit field determines which event will load the active register from the shadow register:

∙Before a write, the CMPCTL[SHDWBFULL] bit can be read to determine if the shadow register is currently full.

∙If CMPCTL[SHDWBMODE] = 1, then the shadow register is disabled and any write or read will go directly to the active register, that is the register actively controlling the hardware.

∙In either mode, the active and shadow registers share the same memory map address.

98

Registers

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 CPU Users Guides Related Documentation From Texas InstrumentsData Manuals Peripheral GuidesTools Guides Application ReportsTrademarks TMS320C28x, C28x are trademarks of Texas InstrumentsSubmit Documentation Feedback Introduction Introduction Submodule OverviewMultiple ePWM Modules ∙ ADC start-of-conversion signals EPWMxSOCA and EPWMxSOCB ∙ PWM output signals EPWMxA and EPWMxB∙ Trip-zone signals TZ1 to TZ6 ∙ Peripheral BusEPWM Submodules and Critical Internal Signal Interconnects Register MappingTime-Base Submodule Registers Offset Size NameDescription 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 ∙ Up-Count Mode Key Time-Base Signals∙ Up-Down-Count Mode ∙ Down-Count ModeTime-Base Period Shadow Register ∙ Time-Base Period Shadow Mode∙ Time-Base Period Immediate Load Mode ∙ 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 SubmoduleCounter-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 ModeCTR=CMPA CTR=CMPBCTR = Cmpb Action-Qualifier Submodule Registers Action-Qualifier AQ SubmodulePurpose of the Action-Qualifier Submodule ∙ Clear Low Action-Qualifier Submodule Possible Input Events∙ Set High ∙ ToggleTB 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 PriorityUse 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 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 EPWMxBControlling 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 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 × TtbclkControlling the PWM-Chopper Submodule PWM-Chopper PC SubmodulePurpose of 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 Submodule17. Trip-Zone Submodule Registers Controlling and Monitoring the Trip-Zone SubmoduleOperational Highlights for the Trip-Zone Submodule ∙ Cycle-by-Cycle CBCScenario a Example 2-8. Trip-Zone Configurations18. Possible Actions On a Trip Event 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 Period Register Tbprd Field Descriptions Time-Base Phase Register Tbphs Field DescriptionsTime-Base Submodule Registers 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 Name Value Description PWM-Chopper Submodule Control Register16. PWM-Chopper Control Register Pcctl Bit Descriptions ReservedChpduty Trip-Zone Submodule Control and Status RegistersPWM-Chopper Control Register Pcctl Bit Descriptions OSHT6 OSHT6 OSHT5 OSHT4 OSHT3 OSHT2 OSHT1CBC6 CBC5 CBC4 CBC3 CBC2 CBC1 CBC6TZB 18. Trip-Zone Control Register Tzctl Field DescriptionsTZB TZA 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