- Global delay_init (fcpu_hz)
- This function is provided for compatibility with ASF applications that may not have been updated to configure the system clock via the common clock service; e.g. sysclk_init() and a configuration header file are used to configure clocks.
- Global F_CPU
- The F_CPU configuration constant is used for compatibility with the Busy-Wait Delay Routines routines. The common loop-based delay routines are designed to use the Clock Management modules while anticipating support for legacy applications assuming a statically defined clock frequency. Applications using a statically configured MCU clock frequency can define F_CPU (Hertz), in which case the common delay routines will use this value rather than calling sysclk_get_cpu_hz() to get the current MCU clock frequency.