The eCAP module represents one
complete capture channel that can be instantiated multiple times, depending on the
target device. In the context of this guide, one eCAP channel has the following
independent key resources:
- Capture inputs can be connected using the Input X-BAR
- 128:1 input multiplexer
- Output X-BAR is used to configure output in APWM mode
- 32-bit time base
(counter)
- 4 x 32-bit time-stamp capture registers (CAP1-CAP4)
- Four-stage sequencer (modulo4 counter) that is synchronized
to external events, eCAP pin rising/falling edges.
- Modulo counter status register (MODCNTRSTS) to indicate sequencer
state
- Independent edge polarity
(rising/falling edge) selection for all four events
- Input capture signal prescaling (from 2-62 or bypass)
- One-shot compare register (two bits) to freeze captures
after 1-4 time-stamp events
- Control for continuous time-stamp captures using a
four-deep circular buffer (CAP1-CAP4) scheme
- Ability to reset event filter, modulo counter, and interrupt flags
- Interrupt capabilities on any of the four capture
events
- EALLOW protection to control registers