Freescale Semiconductor MK22FN256VDC12, Reference Manual

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38.5 Reset overview
The FTM is reset whenever any chip reset occurs.
When the FTM exits from reset:
• the FTM counter and the prescaler counter are zero and are stopped (CLKS[1:0] =
00b);
• the timer overflow interrupt is zero, see Timer Overflow Interrupt ;
• the channels interrupts are zero, see Channel (n) Interrupt ;
• the fault interrupt is zero, see Fault Interrupt ;
• the channels are in input capture mode, see Input Capture mode ;
• the channels outputs are zero;
• the channels pins are not controlled by FTM (ELS(n)B:ELS(n)A = 0:0) (See the table
in the description of CnSC register).
The following figure shows the FTM behavior after the reset. At the reset (item 1), the
FTM counter is disabled (see the description of the CLKS field in the Status and Control
register), its value is updated to zero and the pins are not controlled by FTM (See the
table in the description of CnSC register).
After the reset, the FTM should be configurated (item 2). It is necessary to define the
FTM counter mode, the FTM counting limits (MOD and CNTIN registers value), the
channels mode and CnV registers value according to the channels mode.
Thus, it is recommended to write any value to CNT register (item 3). This write updates
the FTM counter with the CNTIN register value and the channels output with its initial
value (except for channels in output compare mode) (
Counter reset ).
The next step is to select the FTM counter clock by the CLKS[1:0] bits (item 4). It is
important to highlight that the pins are only controlled by FTM when CLKS[1:0] bits are
different from zero (See the table in the description of CnSC register).
Chapter 38 FlexTimer Module (FTM)
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
Freescale Semiconductor, Inc. 945