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3.1
Overview of Multiple Modules
CTR = 0
CTR=CMPB
X
EN
SyncOut
Phase reg
EPWMxA
EPWMxB
SyncIn
Φ
=0
°
3.2
Key Configuration Capabilities
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 3-1
. 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 3-1. Simplified ePWM Module
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 3-2
.
70
Applications to Power Topologies
SPRU791D – November 2004 – Revised October 2007
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Summary of Contents for 28xxx
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Page 8: ...List of Tables 8 SPRU791D November 2004 Revised October 2007 Submit Documentation Feedback...
Page 12: ...Read This First 12 SPRU791D November 2004 Revised October 2007 Submit Documentation Feedback...
Page 68: ...ePWM Submodules 68 SPRU791D November 2004 Revised October 2007 Submit Documentation Feedback...
Page 116: ...Registers 116 SPRU791D November 2004 Revised October 2007 Submit Documentation Feedback...
