NXP Semiconductors K22F series, Reference Manual, Page: 1011 / 1407

channel (n) input
(after the filter
DECAPEN bit
C(n+1)V
FTM counter
clear CH(n+1)F
2
1
2
3
channel input)
DECAP bit
set DECAPEN
set DECAP
5
6
7
8
10
3
4
6
5
Note
- The commands set DECAPEN, set DECAP, clear CH(n)F, and clear CH(n+1)F are made by the user.
4
9
11
12
13
14
9
10
7
15
16
17
18
19
20
21
22
23
24
25
26
27
28
15
16
20
C(n)V
CH(n+1)F bit
CH(n)F bit
clear CH(n)F
1
8 12
22 24
11
19
21 23
Figure 39-85. Dual Edge Capture – Continuous mode for positive polarity pulse width
measurement
39.4.24.4 Period measurement
If the channels (n) and (n+1) are configured to capture consecutive edges of the same
polarity, then the period of the channel (n) input signal is measured. If both channels (n)
and (n+1) are configured to capture rising edges (ELS(n)B:ELS(n)A = 0:1 and ELS(n
+1)B:ELS(n+1)A = 0:1), then the period between two consecutive rising edges is
measured. If both channels (n) and (n+1) are configured to capture falling edges
(ELS(n)B:ELS(n)A = 1:0 and ELS(n+1)B:ELS(n+1)A = 1:0), then the period between
two consecutive falling edges is measured.
The period measurement can be made in One-Shot Capture mode or Continuous Capture
mode .
Chapter 39 FlexTimer Module (FTM)
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
NXP Semiconductors 1011