Enhanced PWM (ePWM) Module
15.2.4.2.3 Counter-Compare B Register (CMPB)
The counter-compare B register (CMPB) is shown in
and described in
Figure 15-77. Counter-Compare B Register (CMPB)
15
0
CMPB
R/W-0
LEGEND: R/W = Read/Write; -n = value after reset
Table 15-68. Counter-Compare B Register (CMPB) Field Descriptions
Bits
Name
Value
Description
15-0
CMPB
0-FFFFh
The value in the active CMPB register is continuously compared to the time-base counter (TBCNT).
When the values are equal, the counter-compare module generates a "time-base counter equal to
counter compare B" event. This event is sent to the action-qualifier where it is qualified and converted it
into one or more actions. These actions can be applied to either the EPWMxA or the EPWMxB output
depending on the configuration of the AQCTLA and AQCTLB registers. The actions that can be defined
in the AQCTLA and AQCTLB registers include:
• Do nothing. event is ignored.
• Clear: Pull the EPWMxA and/or EPWMxB signal low
• Set: Pull the EPWMxA and/or EPWMxB signal high
• Toggle the EPWMxA and/or EPWMxB signal
Shadowing of this register is enabled and disabled by the CMPCTL[SHDWBMODE] bit. By default this
register is shadowed.
• If CMPCTL[SHDWBMODE] = 0, then the shadow is enabled and any write or read will automatically
go to the shadow register. In this case, the CMPCTL[LOADBMODE] bit field determines which event
will load the active register from the shadow register:
• Before a write, the CMPCTL[SHDWBFULL] bit can be read to determine if the shadow register is
currently full.
• If CMPCTL[SHDWBMODE] = 1, then the shadow register is disabled and any write or read will go
directly to the active register, that is the register actively controlling the hardware.
• In either mode, the active and shadow registers share the same memory map address.
15.2.4.3 Action-Qualifier Submodule Registers
lists the memory-mapped registers for the action-qualifier submodule. All other register offset
addresses not listed in
should be considered as reserved locations and the register contents
should not be modified.
Table 15-69. Action-Qualifier Submodule Registers
Offset
Acronym
Register Description
Section
16h
AQCTLA
Action-Qualifier Output A Control Register
18h
AQCTLB
Action-Qualifier Output B Control Register
1Ah
AQSFRC
Action-Qualifier Software Force Register
1Ch
AQCSFRC
Action-Qualifier Continuous Software Force Register
1589
SPRUH73H – October 2011 – Revised April 2013
Pulse-Width Modulation Subsystem (PWMSS)
Copyright © 2011–2013, Texas Instruments Incorporated