AVR_ATMega4809_Atmel_Studio/RTOSDemo/serial/usart.c
AVR_ATMega4809_MPLAB.X/serial/usart.c

AVR_ATMega4809_Atmel_Studio/RTOSDemo/serial/serial.c
AVR_ATMega4809_MPLAB.X/serial/serial.c

AVR_ATMega4809_Atmel_Studio/RTOSDemo/serial/usart.h
AVR_ATMega4809_MPLAB.X/serial/usart.h