siehe Hilfe:
For devices with 2 UARTs, respectively 2 USARTs, there will be two tabs
present: UART0 and UART1, respectively USART0 and USART1.
The functions of configuration check and list boxes will be the same as
described above.
The UART0 (USART0) will use the normal putchar and getchar functions.
In case of interrupt driven buffered communication, UART0 (USART0) will
use the following variables:
rx_buffer0, rx_wr_index0, rx_rd_index0, rx_counter0,
rx_buffer_overflow0,
tx_buffer0, tx_wr_index0, tx_rd_index0, tx_counter0.
The UART1 (USART1) will use the putchar1 and getchar1 functions.
In case of interrupt driven buffered communication, UART1 (USART1) will
use the following variables:
rx_buffer1, rx_wr_index1, rx_rd_index1, rx_counter1,
rx_buffer_overflow1,
tx_buffer1, tx_wr_index1, tx_rd_index1, tx_counter1.
All serial I/O using functions declared in stdio.h, will be done using
UART0 (USART0).