Differences between SCB and UDB implementation
Free routing of IO-Pins, but no use of port4 and greater
Smaller (4 byte) FIFO
I would suggest you to
Use the SCB module when restrictions are alright. The UDB block is quite more versatile and you can use that even for self-made components (after a lot of reading the appropriate manuals)
Hi Bob, in case of UDB UART, will I be able to send and receive data via a hyperterminal such as PuTTY?
Both UARTs can use the USB-UART bridge to display / read from PuTTY. Have a look into your kit's schematic to see which pins you have to connect.