CSCI E-93: Application Note 2

DE2-70 Can't place multiple pins assigned to pin location Pin_AD25
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See http://www.alteraforum.com/forum/showthread.php?t=5851.

When using SW[7] on the DE2-70 board there is a problem with PIN_AD25
that is by default assigned for two purposes.  Messages look similar
to:

Info: Pin ~LVDS195p/nCEO~ is reserved at location AD25
Error: Can't place pins assigned to pin location Pin_AD25 (IOC_X95_Y2_N1)
Info: Pin iSW[7] is assigned to pin location Pin_AD25 (IOC_X95_Y2_N1)

Steps:
  In Quartus-II select menu Assignments > Device...
  Select button "Device and Pin Options..."
  Select the tab "Dual-Purpose Pins"
  Under the list of "Dual-purpose pins:" change the "Value" property of
    nCEO to "Use as regular I/O".
  Click OK