K60P100M100SF2RM Datasheet, PDF (1049/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Chapter 39 FlexTimer (FTM)
When a rising edge occurs in the channel (n) input signal, the FTM counter value is
captured into channel (n) capture buffer. The channel (n) capture buffer value is
transferred to C(n)V register when a falling edge occurs in the channel (n) input signal.
C(n)V register has the FTM counter value when the previous rising edge occurred, and
the channel (n) capture buffer has the FTM counter value when the last rising edge
occurred.
When a falling edge occurs in the channel (n) input signal, the FTM counter value is
captured into channel (n+1) capture buffer. The channel (n+1) capture buffer value is
transferred to C(n+1)V register when the C(n)V register is read.
In the following figure, the read of C(n)V returns the FTM counter value when the event
1 occurred and the read of C(n+1)V returns the FTM counter value when the event 2
occurred.
C(n)V register must be read prior to C(n+1)V register in dual edge capture one-shot and
continuous modes for the read coherency mechanism works properly.
FTM counter
channel (n) input
(after the filter
channel input)
channel (n)
capture buffer
C(n)V
event 1
1
event 2
2
event 3
3
event 4
4
event 5
5
event 6
6
event 7
7
event 8
8
event 9
9
1
3
1
3
5
7
5
9
7
channel (n+1)
capture buffer
C(n+1)V
2
4
6
8
2
read C(n)V
read C(n+1)V
Figure 39-249. Dual Edge Capture Mode Read Coherency Mechanism
39.4.25 Quadrature Decoder Mode
The quadrature decoder mode is selected if (FTMEN = 1) and (QUADEN = 1). The
quadrature decoder mode uses the input signals phase A and B to control the FTM
counter increment and decrement. The following figure shows the quadrature decoder
block diagram.
Each one of input signals phase A and B has a filter that is equivalent to the filter used in
the channels input (Filter for Input Capture Mode). The phase A input filter is enabled by
PHAFLTREN bit and this filter’s value is defined by CH0FVAL[3:0] bits
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.
1049