Hello,
you can use the PSpice model editor to translate IBIS models to PSpice models: select File, New and from the Model menu select “IBIS Translator…” option. The model editor translates IBIS models up to 1.1 version, but with some changes you can modify a IBIS 2.1 version to make it 1.1 compatible. read more details here:
http://www.orcad.com/documents/community.faqs/pspice/020021.aspx
You could also use Intusoft’s IBIS2SPICE converter if you design with ICAP/4. The free version supports IBIS models up to 2.0 version. You can download it here
http://www.intusoft.com/utilities.htm
Bye