Hello. Every microprocessor I have ever used, in the first few pages of the DS, there is a chart showing all the pins down one side, then all their functions in the chart. There are columns for USART, SPI, etc.
I am trying to start a project with ATXMEGA32D4-AU. The DS shows a graphical pin map with PA1... ect, but there is no summary. It looks like you have to actually flip through 8 different sections of a 300+ page DS to make sure your UART and SPI pins aren't doubled up.
I always start a project on this chart noting what I will use the pins for.