FTMx_SC field descriptions (continued)
Field
Description
6
TOIE
Timer Overflow Interrupt Enable
Enables FTM overflow interrupts.
0
Disable TOF interrupts. Use software polling.
1
Enable TOF interrupts. An interrupt is generated when TOF equals one.
5
CPWMS
Center-Aligned PWM Select
Selects CPWM mode. This mode configures the FTM to operate in Up-Down Counting mode.
This field is write protected. It can be written only when MODE[WPDIS] = 1.
0
FTM counter operates in Up Counting mode.
1
FTM counter operates in Up-Down Counting mode.
4–3
CLKS
Clock Source Selection
Selects one of the three FTM counter clock sources.
This field is write protected. It can be written only when MODE[WPDIS] = 1.
00
No clock selected. This in effect disables the FTM counter.
01
System clock
10
Fixed frequency clock
11
External clock
2–0
PS
Prescale Factor Selection
Selects one of 8 division factors for the clock source selected by CLKS. The new prescaler factor affects
the clock source on the next system clock cycle after the new value is updated into the register bits.
This field is write protected. It can be written only when MODE[WPDIS] = 1.
000
Divide by 1
001
Divide by 2
010
Divide by 4
011
Divide by 8
100
Divide by 16
101
Divide by 32
110
Divide by 64
111
Divide by 128
38.3.4 Counter (FTMx_CNT)
The CNT register contains the FTM counter value.
Reset clears the CNT register. Writing any value to COUNT updates the counter with its
initial value, CNTIN.
When BDM is active, the FTM counter is frozen. This is the value that you may read.
Chapter 38 FlexTimer Module (FTM)
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
Freescale Semiconductor, Inc.
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