How to communicate EVAL-MELODY-9 board with UART1 of ADSP 21593 SOM:
By default, the UART1 pins are connected to both J3 connector(SOM) and U17 in the EVAL-MELODY-9 board. If using those UART pins as it is, the signal is going to BF524 via U17.
But, if we want to connect UART1 to PC via USB port, we have to populate resistors R1577 to R1580 (by default they are DNP – refer attached screenshot).
After removed resistors(R1577-R1580) between U17 and J3 connectors, the communication will be estabilshed with SOM by using those UART1 pins.
Schematics is available in the following link EVAL-MELODY-9A Evaluation Board support files (public)