Datasheet

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34.2.9.1 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.
34.2.9.2 Controlling and Monitoring the Digital Compare Submodule
The digital compare submodule operation is controlled and monitored through the following registers:
Table 34-21. Digital Compare Submodule Registers
Register Name Address Offset Shadowed Description
TZDCSEL
(1) (2)
26h No Trip Zone Digital Compare Select Register
DCACTL
(1)
62h No Digital Compare A Control Register
DCTRIPSEL
(1)
60h No Digital Compare Trip Select Register
DCFCTL
(1)
66h No Digital Compare Filter Control Register
DCBCTL
(1)
64h No Digital Compare B Control Register
DCFOFFSET 6Ah Writes Digital Compare Filter Offset Register
DCCAPCTL
(1)
68h No Digital Compare Capture Control Register
DCFWINDOW 6Eh No Digital Compare Filter Window Register
DCFOFFSETCNT 6Ch No Digital Compare Filter Offset Counter Register
DCCAP 72h Yes Digital Compare Counter Capture Register
DCFWINDOWCNT 70h No Digital Compare Filter Window Counter Register
(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.
1766
Enhanced Pulse Width Modulator (ePWM) Module SPNU562–May 2014
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