NXP Semiconductors K22F series, Reference Manual, Page: 1008 / 1407

• The CH(n+1)F, CH(n+1)IE, MS(n+1)A, ELS(n+1)B, and
ELS(n+1)A bits are channel (n+1) bits.
• The Dual Edge Capture mode must be used with
ELS(n)B:ELS(n)A = 0:1 or 1:0, ELS(n+1)B:ELS(n+1)A =
0:1 or 1:0 and the FTM counter in
Free running counter .
39.4.24.1 One-Shot Capture mode
The One-Shot Capture mode is selected when (DECAPEN = 1), and (MS(n)A = 0). In
this capture mode, only one pair of edges at the channel (n) input is captured. The
ELS(n)B:ELS(n)A bits select the first edge to be captured, and ELS(n+1)B:ELS(n+1)A
bits select the second edge to be captured.
The edge captures are enabled while DECAP bit is set. For each new measurement in
One-Shot Capture mode, first the CH(n)F and CH(n+1) bits must be cleared, and then the
DECAP bit must be set.
In this mode, the DECAP bit is automatically cleared by FTM when the edge selected by
channel (n+1) is captured. Therefore, while DECAP bit is set, the one-shot capture is in
process. When this bit is cleared, both edges were captured and the captured values are
ready for reading in the C(n)V and C(n+1)V registers.
Similarly, when the CH(n+1)F bit is set, both edges were captured and the captured
values are ready for reading in the C(n)V and C(n+1)V registers.
39.4.24.2 Continuous Capture mode
The Continuous Capture mode is selected when (DECAPEN = 1), and (MS(n)A = 1). In
this capture mode, the edges at the channel (n) input are captured continuously. The
ELS(n)B:ELS(n)A bits select the initial edge to be captured, and ELS(n+1)B:ELS(n+1)A
bits select the final edge to be captured.
The edge captures are enabled while DECAP bit is set. For the initial use, first the
CH(n)F and CH(n+1)F bits must be cleared, and then DECAP bit must be set to start the
continuous measurements.
When the CH(n+1)F bit is set, both edges were captured and the captured values are
ready for reading in the C(n)V and C(n+1)V registers. The latest captured values are
always available in these registers even after the DECAP bit is cleared.
Functional description
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
1008 NXP Semiconductors