Espressif ESP32 Technical Reference Manual page 430

16 Motor Control PWM (PWM)
16.3.3.1 PWM Generator Submodule
Purpose of the PWM Generator Submodule
In this submodule, important timing events are generated or imported. The events are then converted into
specific actions to generate the desired waveforms at the PWMxA and PWMxB outputs.
The PWM generator submodule performs the following actions:
• Generation of timing events based on time stamps configured using the A and B registers. Events happen
when the following conditions are satisfied:
– UTEA: the PWM timer is counting up and its value is equal to register A.
– UTEB: the PWM timer is counting up and its value is equal to register B.
– DTEA: the PWM timer is counting down and its value is equal to register A.
– DTEB: the PWM timer is counting down and its value is equal to register B.
• Generation of U/DT1, U/DT2 timing events based on fault or synchronization events.
• Management of priority when these timing events occur concurrently.
• Qualification and generation of set, clear and toggle actions, based on the timing events.
• Controlling of the PWM duty cycle, depending on configuration of the PWM generator submodule.
• Handling of new time stamp values, using shadow, registers to prevent glitches in the PWM cycle.
PWM Operator Shadow Registers
The time stamp registers A and B, as well as action configuration registers
are shadowed. Shadowing provides a way of updating registers in sync with the hardware. For a description of
the shadow registers, please see 16.3.2.3.
Timing Events
For convenience, all timing signals and events are summarized in Table 16-2.
Signal
DTEP
DTEZ
DTEA
DTEB
DT0 event
DT1 event
UTEP
UTEZ
UTEA
UTEB
UT0 event
UT1 event
Espressif Systems
Table 16-2. Timing Events Used in PWM Generator
Event Description
PWM timer value is equal to the period register value
PWM timer value is equal to zero
PWM timer value is equal to A register
PWM timer value is equal to B register
Based on fault or synchronization events
Based on fault or synchronization events
PWM timer value is equal to the period register value
PWM timer value is equal to zero
PWM timer value is equal to A register
PWM timer value is equal to B register
Based on fault or synchronization events
Based on fault or synchronization events
Submit Documentation Feedback
PWM_GENx_A_REG
430
and PWM_GENx_B_REG
PWM Timer Operation
PWM timer counts down.
PWM timer counts up.
ESP32 TRM (Version 5.2)