Table 38-251. Channel DMA transfer request (continued)
DMA
CHnIE
Channel DMA Transfer Request
Channel Interrupt
1
1
The channel DMA transfer request is generated if
(CHnF = 1).
The channel interrupt is not generated.
If DMA = 1, the CHnF bit is cleared either by channel DMA transfer done or reading
CnSC while CHnF is set and then writing a zero to CHnF bit according to CHnIE bit. See
the following table.
Table 38-252. Clear CHnF bit when DMA = 1
CHnIE
How CHnF Bit Can Be Cleared
0
CHnF bit is cleared either when the channel DMA transfer is done or by reading CnSC while CHnF is set and
then writing a 0 to CHnF bit.
1
CHnF bit is cleared when the channel DMA transfer is done.
38.4.24 Dual Edge Capture mode
The Dual Edge Capture mode is selected if DECAPEN = 1. This mode allows to measure
a pulse width or period of the signal on the input of channel (n) of a channel pair. The
channel (n) filter can be active in this mode when n is 0 or 2.
channel (n) input
system clock
synchronizer
Filter*
Dual edge capture
mode logic
is filter
enabled?
FTM counter
* Filtering function for dual edge capture mode is only available in the channels 0 and 2
channel (n)
interrupt
channel (n+1)
interrupt
C(n+1)V[15:0]
C(n)V[15:0]
CH(n+1)IE
CH(n+1)F
CH(n)IE
CH(n)F
FTMEN
DECAPEN
DECAP
MS(n)A
ELS(n)B:ELS(n)A
ELS(n+1)B:ELS(n+1)A
CLK
CLK
D
Q
D
Q
0
1
Figure 38-246. Dual Edge Capture mode block diagram
The MS(n)A bit defines if the Dual Edge Capture mode is one-shot or continuous.
Functional description
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
928
Freescale Semiconductor, Inc.