The appropriate settings of the phase A and phase B input filters are important to avoidglitches that may cause oscillation on the FTM counter value. The preceding figuresshow examples of oscillations that can be caused by poor input filter setup. Thus, it isimportant to guarantee a minimum pulse width to avoid these oscillations.41.5.28 Debug modeWhen the chip is in Debug mode, the BDMMODE[1:0] bits select the behavior of theFTM counter, the channel (n) CHF bit, the channels output, and the writes to the MOD,CNTIN, and C(n)V registers according to the following table.Table 41-20. FTM behavior when the chip Is in Debug modeBDMMODE FTMCounterchannel (n)CHF bit FTM Channels Output Writes to MOD, CNTIN, and C(n)V Registers00 Stopped can be set Functional mode Writes to these registers bypass the registersbuffers01 Stopped is not set The channels outputs are forcedto their safe value according toPOLn bitWrites to these registers bypass the registersbuffers10 Stopped is not set The channels outputs are frozenwhen the chip enters in DebugmodeWrites to these registers bypass the registersbuffers11 Functionalmodecan be set Functional mode Functional modeNote that if BDMMODE[1:0] = 2’b00 then the channels outputs remain at the valuewhen the chip enters in Debug mode, because the FTM counter is stopped. However, thefollowing situations modify the channels outputs in this Debug mode.• Write any value to CNT register; see Counter reset. In this case, the FTM counter isupdated with the CNTIN register value and the channels outputs are updated to theinitial value – except for those channels set to Output Compare mode.• FTM counter is reset by PWM Synchronization mode; see FTM countersynchronization. In this case, the FTM counter is updated with the CNTIN registervalue and the channels outputs are updated to the initial value – except for channelsin Output Compare mode.• In the channels outputs initialization, the channel (n) output is forced to the CH(n)OIbit value when the value 1 is written to INIT bit. See Initialization.Chapter 41 FlexTimer Module (FTM)MWCT101xS Series Reference Manual, Rev. 3, 07/2019NXP Semiconductors 1271
