ATxmega have many clock options. This introduce clk_init into cpu_init
to allow user select between a default configuration or perform fine
clock tune.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
The XMEGA CPU have a Programmable Multilevel Interrupt Controller.
This enables all three PMIC levels. By default, all interrupts are
preconfigured as LOW Level without Round Robin queue. This works
as any MCU with interrupt enabled.
In order to get benefit from Multilevel Interrupts user need increase
the interrupt level by own.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Some mega boards enabling global irq at board_init. This moves that
responsability to cpu/avr8_common to create a common point to all
variants.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Split atmega_common code into avr8_common folder. This moves common
avr8 code to be used for all avr8 variants: tiny, mega and xmega.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>