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SPRUH91D–March 2013–Revised September 2016
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Enhanced High-Resolution Pulse-Width Modulator (eHRPWM)
14.2 Architecture
Seven submodules are included in every ePWM peripheral. There are some instances that include a high-
resolution submodule that allows more precise control of the PWM outputs. Each of these submodules
performs specific tasks that can be configured by software.
14.2.1 Overview
Table 14-2 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 Section 14.2.4 for relevant details.
Table 14-2. Submodule Configuration Parameters
Submodule Configuration Parameter or Option Reference
Time-base (TB)
• Scale the time-base clock (TBCLK) relative to the system clock
(SYSCLKOUT).
• Configure the PWM time-base counter (TBCNT) 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.
Section 14.2.3
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
Section 14.2.4
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
Section 14.2.5
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.
Section 14.2.6
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.
Section 14.2.7
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