CEVT1
CEVT2
CEVT3
CEVT4
CEVT1
FFFFFFFF
CTR[0−31]
00000000
CAPx pin
t
MOD4
CTR
CAP1
CAP2
CAP3
CAP4
Capture registers [1−4]
CEVT2
CEVT1
CEVT3
CEVT4
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
0
1
2
3
0
1
2
3
0
XX
t
1
t
5
XX
t
2
t
6
XX
t
3
t
7
XX
t
4
t
8
Polarity selection
t
Application of the ECAP Module
849
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
C28 Enhanced Capture (eCAP) Module
8.7.2 Example 2 - Absolute Time-Stamp Operation Rising and Falling Edge Trigger
In
the eCAP operating mode is almost the same as in the previous section except capture
events are qualified as either rising or falling edge, this now gives both period and duty cycle information,
i.e: Period1 = t
3
– t
1
, Period2 = t
5
– t
3
, …etc. Duty Cycle1 (on-time %) = (t
2
– t
1
) / Period1 x 100%, etc. Duty
Cycle1 (off-time %) = (t
3
– t
2
) / Period1 x 100%, etc.
Figure 8-24. Capture Sequence for Absolute Time-stamp With Rising and Falling Edge Detect
