Each EPWM module supports the following features:
- Dedicated 16-bit time-base counter with period and frequency control
- Two PWM outputs (EPWMxA and EPWMxB) that can be used in the following configurations:
- Two independent PWM outputs with single-edge operation
- Two independent PWM outputs with dual-edge symmetric operation
- One independent PWM output with dual-edge asymmetric operation
- Asynchronous override control of PWM signals through software
- Programmable phase-control support for lag or lead operation relative to other EPWM modules
- Hardware-locked (synchronized) phase relationship on a cycle-by-cycle basis
- Dead-band generation with independent rising and falling edge delay control
- Programmable trip zone allocation of both cycle-by-cycle trip and one-shot trip on fault conditions
- A trip condition can force either high, low, or high-impedance state logic levels at PWM outputs
- Allows events to trigger both CPU interrupts and ADC start of conversions
- Programmable event prescaling minimizes CPU overhead on interrupts
- PWM chopping by high-frequency carrier signal, useful for pulse transformer gate drives
- High-resolution module with programmable delay line:
- Programmable on a per PWM period basis
- Can be inserted either on the rising edge or falling edge of the PWM pulse or both or not at all.
Each EPWM module is connected to the
input/output signals shown in Figure 12-2598. The
signals are described in detail in subsequent sections.
The order in which the EPWM modules
are connected may differ from what is shown in Figure 12-2598. See Daisy-Chain Connectivity between EPWM Modules for the actual
synchronization scheme implemented in the device. Each EPWM module consists of eight
submodules and is connected within a system via the signals shown in Figure 12-2599.
Figure 12-2596 Submodules and Signal Connections for an EPWM Module
Figure 12-2600 shows
more internal details of a single EPWM module. The main signals used by the EPWM
module are:
- PWM output signals (EPWMxA
and EPWMxB). The PWM output signals are made available external to
the device through the GPIO peripheral described in the system control and
interrupts guide for the device.
- Trip-zone signals (
TZ0 to TZ5). These
input signals alert the EPWM module of an external fault condition. Each
module on a device can be configured to either use or ignore any of the
trip-zone signals. The trip-zone signal can be configured as an asynchronous
input through the GPIO peripheral.
- Time-base synchronization
input (EPWMxSYNCI) and output (EPWMxSYNCO) signals. The
synchronization signals daisy chain the EPWM modules together. Each module
can be configured to either use or ignore its synchronization input. The
clock synchronization input and output signal are brought out to pins for
EPWM0 (EPWM module 0) and EPWM3. The EPWM5 synchronization output
(EPWM5SYNCO) is also connected to the input SYNCIN of the Enhanced Capture
Module (ECAP0).
- ADC start-of-conversion
signals (EPWMxSOCA and EPWMxSOCB). Each EPWM module has two ADC
start of conversion signals (one for each sequencer). Any EPWM module can
trigger a start of conversion for either sequencer. Which event triggers the
start of conversion is configured in the Event-Trigger submodule of the
EPWM.
- Peripheral Bus. The
peripheral bus is 32-bits wide and allows both 16-bit and 32-bit writes to
the EPWM register file.
Figure 12-2600 also
shows the key internal submodule interconnect signals. Each submodule is described
in Section 12.4.2.4.