Are the IOE programmable delay values for D1-D6, stated in Stratix IV datasheet, represents the total delay or a base delay with respective to D1-D6 available settings?

Description

The IOE programmable delay values for D1-D6, stated in Stratix® IV datasheet, represents the total delay with respective to D1-D6 available settings. The approximate delay beteen steps would be the D1-D6 total delay divided by its respective available settings.