A logic option that implements slow low-to-high or high-to-low transitions on output pins to help reduce switching noise. When a large number of output pins switch simultaneously, pins that use the Slow Slew Rate option help reduce switching noise.

This option is ignored if it is assigned to anything other than an output or bidirectional pin, or a top-level design entity containing output or bidirectional pins. This option is available for all Altera^® devices supported by the Quartus^® II software.