You can use the callback function. Here are the steps-
1. In the UART component customizer, enable the type of RX interrupt you want. For example, "RX FIFO not Empty"
2. In the cyapicallbacks.h file, add the following statements to declare the callback back function-
In the DBUS_SPI_UART_INT.c (under generated_source), you will notice that the callback function is activated under
3. Write the function DBUS_SPI_UART_ISR_EntryCallback() in your .c file.
Note that you can either use EntryCallBack() function or ExitCallBack() function. As you SW buffer is not enabled, it will not make any difference here. But if you enable SW buffer (by keeping RX or TX buffer size greater than 8), you need to be careful about the selection.