Information

FlexTimer input triggers can be from comparators, ADC or other sub modules to initiate
timer functions automatically. These triggers can be linked in a variety of ways during
integration of the sub modules so please note carefully the options available for used
FlexTimer configuration.
Several FlexTimers may be synchronized to provide a larger timer with their counters
incrementing in unison, assuming the initialization, the input clocks, the initial and final
counting values are the same in each FlexTimer.
All main user access registers are buffered to ease the load on the executing software. A
number of trigger options exist to determine which registers are updated with this user
defined data.
37.1.2 Features
The FTM features include:
• FTM source clock is selectable
• Source clock can be the system clock, the fixed frequency clock, or an external
clock
• Fixed frequency clock is an additional clock input to allow the selection of an on
chip clock source other than the system clock
• Selecting external clock connects FTM clock to a chip level input pin therefore
allowing to synchronize the FTM counter with an off chip clock source
• Prescaler divide-by 1, 2, 4, 8, 16, 32, 64, or 128
• FTM has a 16-bit counter
• It can be a free-running counter or a counter with initial and final value
• The counting can be up or up-down
• Each channel can be configured for input capture, output compare, or edge-aligned
PWM mode
• In input capture mode
• the capture can occur on rising edges, falling edges or both edges
• an input filter can be selected for some channels
• In output compare mode the output signal can be set, cleared, or toggled on match
• All channels can be configured for center-aligned PWM mode
Introduction
K20 Sub-Family Reference Manual, Rev. 6, Nov 2011
848 Freescale Semiconductor, Inc.