UART_S1
while (!(uart_getreg(bas, UART_S1) & UART_S1_TDRE))
usr1 = uart_getreg(bas, UART_S1);
while (!(uart_getreg(bas, UART_S1) & UART_S1_RDRF))
usr1 = uart_getreg(bas, UART_S1);
while (uart_getreg(bas, UART_S1) & UART_S1_RDRF) {