Registers
784
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
C28 Enhanced Pulse Width Modulator (ePWM) Module
Table 7-44. Counter-Compare B Register (CMPB) Field Descriptions
Bit
Field
Description
15-0
CMPB
The value in the active CMPB register is continuously compared to the time-base counter (TBCTR). 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.
Figure 7-95. Counter-Compare C Register (CMPC)
15
0
CMPC
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 7-45. Counter-Compare C Register (CMPC) Field Descriptions
Bit
Field
Description
15-0
CMPC
The value in the active CMPC register is continuously compared to the time-base counter (TBCTR). When the
values are equal, the counter-compare module generates a "time-base counter equal to counter compare C"
event.
Shadowing of this register is enabled and disabled by the CMPCTL2[SHDWCMODE] bit. By default this
register is shadowed.
• If CMPCTL2[SHDWCMODE] = 0, then the shadow is enabled and any write or read will automatically go to
the shadow register. In this case, the CMPCTL2[LOADCMODE] bit field determines which event will load
the active register from the shadow register:
• If CMPCTL2[SHDWCMODE] = 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.
Figure 7-96. Counter-Compare D Register (CMPD)
15
0
CMPD
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset