CTR = CMPB
CTR = CMPA
CTR_Dir
CTR = 0
CTR = PRD
Dead
Band
(DB)
Counter
Compare
(CC)
Action
Qualifier
(AQ)
EPWMxA
EPWMxB
CTR = CMPB
CTR = 0
EPWMxINT
EPWMxA
EPWMxB
TZ1 to TZn
CTR = CMPA
Time-Base
(TB)
CTR = PRD
CTR = 0
CTR_Dir
EPWMxSYNCI
EPWMxSYNCO
EPWMxTZINT
PWM-
chopper
(PC)
Event
Trigger
and
Interrupt
(ET)
Trip
Zone
(TZ)
GPIO
MUX
Interrupt
controller
Interrupt
controller
Enhanced PWM (ePWM) Module
15.2.2.6 Dead-Band Generator (DB) Submodule
illustrates the dead-band generator submodule within the ePWM module.
Figure 15-33. Dead-Band Generator Submodule
15.2.2.6.1 Purpose of the Dead-Band Submodule
The "Action-qualifier (AQ) Module" section discussed how it is possible to generate the required dead-
band by having full control over edge placement using both the CMPA and CMPB resources of the ePWM
module. However, if the more classical edge delay-based dead-band with polarity control is required, then
the dead-band generator submodule should be used.
The key functions of the dead-band generator submodule are:
•
Generating appropriate signal pairs (EPWMxA and EPWMxB) with dead-band relationship from a
single EPWMxA input
•
Programming signal pairs for:
–
Active high (AH)
–
Active low (AL)
–
Active high complementary (AHC)
–
Active low complementary (ALC)
•
Adding programmable delay to rising edges (RED)
•
Adding programmable delay to falling edges (FED)
•
Can be totally bypassed from the signal path (note dotted lines in diagram)
15.2.2.6.2 Controlling and Monitoring the Dead-Band Submodule
The dead-band generator submodule operation is controlled and monitored via the following registers:
Table 15-33. Dead-Band Generator Submodule Registers
Acronym
Register Description
Address Offset
Shadowed
DBCTL
Dead-Band Control Register
1Eh
No
DBRED
Dead-Band Rising Edge Delay Count Register
20h
No
DBFED
Dead-Band Falling Edge Delay Count Register
22h
No
1534Pulse-Width Modulation Subsystem (PWMSS)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated