4.5.1. Functional description

Two timers are defined as the default provided, although you can easily expand this through extra instantiations of the FRC block. The same principle of simple expansion has been applied to the register configuration, enabling more complex counters to be used. For each timer, the following modes of operation are available:

Free-running mode

The counter wraps after reaching its zero value, and continues to count down from the maximum value. This is the default mode.

Periodic timer mode

The counter generates an interrupt at a constant interval, reloading the original value after wrapping past zero.

One-shot timer mode

The counter generates an interrupt once. When the counter reaches zero, it halts until reprogrammed by the user. This can be achieved by either clearing the One Shot Count bit in the control register, in which case the count proceeds according to the selection of Free-running or Periodic mode, or by writing a new value to the Load Value register.

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