Datasheet

CTR = 0
CTR=CMPB
X
EN
SyncOut
Phase reg
EPWMxA
EPWMxB
SyncIn
Φ=0°
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34.3 Application Examples
An ePWM module has all the local resources necessary to operate completely as a standalone module or
to operate in synchronization with other identical ePWM modules.
34.3.1 Overview of Multiple Modules
Previously in this user's guide, all discussions have described the operation of a single module. To
facilitate the understanding of multiple modules working together in a system, the ePWM module
described in reference is represented by the more simplified block diagram shown in Figure 34-51. This
simplified ePWM block shows only the key resources needed to explain how a multiswitch power topology
is controlled with multiple ePWM modules working together.
Figure 34-51. Simplified ePWM Module
34.3.2 Key Configuration Capabilities
The key configuration choices available to each module are as follows:
• Options for SyncIn
– Load own counter with phase register on an incoming sync strobe—enable (EN) switch closed
– Do nothing or ignore incoming sync strobe—enable switch open
– Sync flow-through - SyncOut connected to SyncIn
– Master mode, provides a sync at PWM boundaries—SyncOut connected to CTR = PRD
– Master mode, provides a sync at any programmable point in time—SyncOut connected to CTR =
CMPB
– Module is in standalone mode and provides No sync to other modules—SyncOut connected to X
(disabled)
• Options for SyncOut
– Sync flow-through - SyncOut connected to SyncIn
– Master mode, provides a sync at PWM boundaries—SyncOut connected to CTR = PRD
– Master mode, provides a sync at any programmable point in time—SyncOut connected to CTR =
CMPB
– Module is in standalone mode and provides No sync to other modules—SyncOut connected to X
(disabled)
For each choice of SyncOut, a module may also choose to load its own counter with a new phase value
on a SyncIn strobe input or choose to ignore it, i.e., via the enable switch. Although various combinations
are possible, the two most common—master module and slave module modes—are shown in Figure 34-
52.
1772
Enhanced Pulse Width Modulator (ePWM) Module SPNU562–May 2014
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