NXP Semiconductors KE1xF Series, Reference Manual, Page: 1139 / 1483

• If TROT = 1, counter is loaded on each trigger; else, counter is loaded on every
T_EN rising edge or timeout rising edge (timeout not used in Capture modes).
• If TSOT = 1, counter will start to decrement on trigger. Subsequent triggers are
ignored till a counter timeout. If TSOT = 0, counter decrements immediately from
the next clock edge. TSOT has no effect when channel is Chained or in Capture
mode.
These bits affect the timer operation differently in different timer modes:
• In 32-bit Periodic Counter and Dual 16-bit Periodic Counter modes, all bits (TSOT,
TSOI & TROT) affect the timer operation as described above.
• In 32-bit Trigger Accumulator mode, only TSOI bit controls the timer function.
TROT & TSOT bits have no effect on timer operation.
• In 32-bit Input Trigger Capture mode, TSOI and TROT bits control the timer
function. TSOT bit has no effect on timer operation.
42.5.4 Channel Chaining
Individual timer channels can be chained together to achieve a larger value of timeout.
Chaining the timer channel causes them to work in a 'nested loop' manner thereby leading
to an effective timeout value of TVAL
CHn
× (TVAL
CHn-1
+ 1).
The channels are chained by setting the CHAIN bit in corresponding channel's TCTRLn
register. When a channel is chained, that channel's timer decrements on previous
channel's timeout pulse, irrespective of the timer mode (MODE bits). The TSOT bit does
not have any effect if the channel timer (Channel 'n') is chained to previous channel's
timer (Channel 'n-1').
42.6 Usage Guide
42.6.1 Periodic timer/counter
LPIT typical usage is to generate periodic trigger pulses and interrupts.
Example: LPIT channel0 trigger a periodic interrupt every 1 second
• Enable the LPIT module clock;
• Reset the timer channels and registers;
• Setup timer operation in debug and doze modes and enable the module;
• Setup the channel counters operation mode to "32-bit Periodic Counter",and keep
default values for the trigger source;
Chapter 42 Low-power Periodic Interrupt Timer (LPIT)
Kinetis KE1xF Sub-Family Reference Manual, Rev. 4, 06/2019
NXP Semiconductors 1139