20.3.1 Definitions

The following definitions are used throughout the documentation:

Table 20-1. Timer/Counter Definitions
Name Description
BOTTOM The counter reaches BOTTOM when it becomes 0x0000.
MAX The counter reaches MAXimum when it becomes all ones.
TOP The counter reaches TOP when it becomes equal to the highest value in the count sequence.
UPDATE The update condition is met when the timer/counter reaches BOTTOM or TOP, depending on the Waveform Generator mode. Buffered registers with valid buffer values will be updated unless the Lock Update (LUPD) bit in the TCAn.CTRLE register has been set.
CNT Counter register value.
CMP Compare register value.
PER Period register value.

In general, the term timer is used when the timer/counter is counting periodic clock ticks. The term counter is used when the input signal has sporadic or irregular ticks. The latter can be the case when counting events.