ePWM Submodules
2049
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Enhanced Pulse Width Modulator (ePWM) Module
35.2.9.1 Purpose of the Digital Compare Submodule
The key functions of the digital compare submodule are:
•
TZ1, TZ2, and TZ3 inputs generate Digital Compare A High/Low (DCAH, DCAL) and Digital Compare
B High/Low (DCBH, DCBL) signals.
•
DCAH/L and DCBH/L signals trigger events which can then either be filtered or fed directly to the trip-
zone, event-trigger, and time-base submodules to:
–
generate a trip zone interrupt
–
generate an ADC start of conversion
–
force an event
–
generate a synchronization event for synchronizing the ePWM module TBCTR.
•
Event filtering (blanking window logic) can optionally blank the input signal to remove noise.
35.2.9.2 Controlling and Monitoring the Digital Compare Submodule
The digital compare submodule operation is controlled and monitored through the following registers:
(1)
These registers are writable only in privileged mode.
(2)
The TZDCSEL register is part of the trip-zone submodule but is mentioned again here because of its functional significance to
the digital compare submodule.
Table 35-21. Digital Compare Submodule Registers
Register Name
Address Offset
Shadowed
Description
TZDCSEL
(1) (2)
24h
No
Trip Zone Digital Compare Select Register
DCACTL
(1)
60h
No
Digital Compare A Control Register
DCTRIPSEL
(1)
62h
No
Digital Compare Trip Select Register
DCFCTL
(1)
64h
No
Digital Compare Filter Control Register
DCBCTL
(1)
66h
No
Digital Compare B Control Register
DCFOFFSET
68h
Writes
Digital Compare Filter Offset Register
DCCAPCTL
(1)
6Ah
No
Digital Compare Capture Control Register
DCFWINDOW
6Ch
No
Digital Compare Filter Window Register
DCFOFFSETCNT
6Eh
No
Digital Compare Filter Offset Counter Register
DCCAP
70h
Yes
Digital Compare Counter Capture Register
DCFWINDOWCNT
72h
No
Digital Compare Filter Window Counter Register