Altera provides a RAM-based shift register megafunction called ALTSHIFT_TAPS
that contains additional features not found in a conventional shift register. Traditional
shift registers implemented with standard flip-flops use many logic cells for large
shift registers. The ALTSHIFT_TAPS megafunction is implemented in the device
memory blocks, saving logic cells and routing resources. In a complicated design such
as a digital signal processing (DSP) application that requires local data storage, it is
more efficient to implement an ALTSHIFT_TAPS megafunction as the shift register.