Table 39-7. CnV register update (continued)
When Then CnV register is updated
• If the selected mode is Output Compare, then CnV register is updated on the
next FTM counter change, end of the prescaler counting, after CnV register
was written.
• If the selected mode is EPWM, then CnV register is updated after CnV
register was written and the FTM counter changes from MOD to CNTIN. If
the FTM counter is at free-running counter mode then this update occurs
when the FTM counter changes from 0xFFFF to 0x0000.
• If the selected mode is CPWM, then CnV register is updated after CnV
register was written and the FTM counter changes from MOD to (MOD –
0x0001).
• CLKS[1:0] ≠0:0, and
• FTMEN = 1
According to the selected mode, that is:
• If the selected mode is output compare then CnV register is updated
according to the SYNCEN bit. If (SYNCEN = 0) then CnV register is updated
after CnV register was written at the next change of the FTM counter, the
end of the prescaler counting. If (SYNCEN = 1) then CnV register is updated
by the C(n)V and C(n+1)V register synchronization.
• If the selected mode is not output compare and (SYNCEN = 1) then CnV
register is updated by the C(n)V and C(n+1)V register synchronization.
39.4.11 PWM synchronization
The PWM synchronization provides an opportunity to update the MOD, CNTIN, CnV,
OUTMASK, INVCTRL and SWOCTRL registers with their buffered value and force the
FTM counter to the CNTIN register value.
Note
The legacy PWM synchronization (SYNCMODE = 0) is a
subset of the enhanced PWM synchronization (SYNCMODE =
1). Thus, only the enhanced PWM synchronization must be
used.
39.4.11.1
Hardware trigger
Three hardware trigger signal inputs of the FTM module are enabled when TRIGn = 1,
where n = 0, 1 or 2 corresponding to each one of the input signals, respectively. The
hardware trigger input n is synchronized by the system clock. The PWM synchronization
with hardware trigger is initiated when a rising edge is detected at the enabled hardware
trigger inputs.
If (HWTRIGMODE = 0) then the TRIGn bit is cleared when 0 is written to it or when the
trigger n event is detected.
Chapter 39 FlexTimer Module (FTM)
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
NXP Semiconductors 973
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