Hi Minnu,
Sorry for the delayed response, you may directly use NFC of BF52x to interface NAND flash devices instead of using GPIO or EBIU. The BF52x processor NFC supports SLC NAND flash devices unlimited in size and provides may other features please refer Chapter 20 NAND Flash Controller chapter in BF52x HRM for more detailed and additional information<http://www.analog.com/static/imported-files/processor_manuals/ADSP-BF52x_hwr_rev1.2.pdf>, using GPIO or EBIU interface would be complex, however if you still need to use GPIO or EBIU then there is a app note EE-302<http://www.analog.com/static/imported-files/application_notes/EE-302.pdf> which describes how to interface NAND flash devices to BF53x via EBIU or GPIO you may use this as a reference for your design, unfortunately there is no code example available.
Regards,
Suraj.
