Foundational crate for retrieving details about the target AVR being compiled for.
This crate currently exposes the CPU frequency that is being configured for.
All crates that depend on this crate will require
$AVR_CPU_FREQUENCY_HZ when targeting
AVR. The frequency will then be available in the
It is not necessary to set this variable when AVR is not being targeted, for example, when running integration tests on the host machine.
The clock frequency of the current AVR microcontroller.