Submodule Configuration Parameters - Texas Instruments Concerto F28M36 Series Technical Reference Manual

ePWM Submodules
7.2 ePWM Submodules
Eight submodules are included in every ePWM peripheral. Each of these submodules performs specific
tasks that can be configured by software.
7.2.1 Overview
Table 7-3 lists the eight 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
Submodule
Time-base (TB)
Counter-compare (CC)
Action-qualifier (AQ)
Dead-band (DB)
PWM-chopper (PC)
678
C28 Enhanced Pulse Width Modulator (ePWM) Module
Section 7.2.3 for relevant details.
Table 7-3. Submodule Configuration Parameters
Configuration Parameter or Option
• 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.
• Simultaneous writes to the TBPRD registers on all PWM's corresponding to the configuration on
EPWMXLINK.
• 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.
• 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
• Specify the programmable delay for interrupt and SOC generation with additional comparators
• Simultaneous writes to the CMPA, CMPB, CMPC, CMPD registers on all PWM's corresponding
to the configuration on EPWMXLINK.
• 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
• 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.
• Option to enable half-cycle clocking for double resolution.
• Allow ePWMxB phase shifting with respect to the ePWMxA output.
• 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.
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SPRUHE8E – October 2012 – Revised November 2019
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