What happens when I check the "Reduced device drivers" check box in the system library properties page in the Nios II IDE?

Description When checked, the compiler will include the reduced version of device drivers for all devices that provide small drivers. This reduces memory footprint at the expense of functionality. For example, the UART and JTAG UARTs use a polling method instead of an interrupt driven method.  Refer to the Nios II Processor Reference Handbook and the device driver source code for more details.  This document can be found in the Nios II installation at <Nios II installation>/documents/n2cpu_nii5v1.pdf and on the Altera web site at http://www.altera.com/literature/lit-nio2.jsp.