How to use the Uart driver with interrupts

To make printf non-blocking needs a fifo somewhere - this could be software (using interrupts) or could be hardware. Both need the memory somewhere, and when the fifo is full will block.

With a small hardware fifo and a larger sw fifo you don't necessarily need interrupts - the embeded schedule loop could refill the hw fifo.

Dunno what the altera library code you might be using actually tries to do though!