Stratix IV Programmable Pull-Up Resistor

Hi,

I have to use Stratix IV E EP4SE530H35C2NES on Altera develop board.

I need to control the pull-up/down enable by design,

I mean there is a behav. description for the pad like this:

bufif1(pull1, pull0) ( pad, pus, ipp_pue );

these pads are designed for custom silicon.

Where:

ipp_pue => enable pull-up/down

pus => 1->pull-up 0->pull-down

In Stratix IV handbook(stratix4_handbook.pdf) is showed

the "Stratix IV IOE structure"(Figure 6-17), there is

a "Programmable Pull-Up Resistor".

In the documentation is not clear, for me the way, to

control it.

How can I control this resistor by design?

Can I configure the IOE for pull-down?

Thank in advance for your help.