This directory contains two types of files: the RFA1 microcontroller
specific HplAtmRfa1* and TimerConfig.h files, and everything else which is 
built on top of these and could support other microcontrollers in the 
ATmega family.

The HplAtmRfa1* files provides very basic access to the various timers and 
handle power management. The TimerConfig.h file configures the rest of the
system.

We build two separate timers on top of the HPL layer: the TMcu timer from 
which we derive all TMicro timers and alarms. The TMcu timer is built on
top of one of the 16-bit hardware timer. This timer stops counting if the
microcontroller is in one of the power save modes. However, if one of the
alarms is set (or a capture is enabled), then this prevents the mcu to stop.
Note, that depending on the clock frequency of the MCU the TMcu timer can run
with any frequency between 1 and 16 MHz. 

The other timer is the real time clock, which is derived from the 8-bit 32 
KHz async timer/counter. You can set various prescale settings here, so the
TRtc can run at 1 KHz, 4 KHz or 32 KHz. All TMilli timers and alarms are 
derived from this.

The RFA1 has a symbol counter also driven by the external 32 KHz crystal, but 
it runs at 62.5 KHz. This is independent of the RTC clock, and in fact it is
much more efficient than the 8-bit 32 KHz timer. You can select in TimerConfig.h
to use this for the TRtc (and TMilli).
