Description
A pull-up resistor to Vccio is recommended on the DATA input signal if the only configuration scheme implemented on the board is Passive Serial using a download cable (ByteBlasterMV, ByteBlaster II, or MasterBlaster). This pull-up resistor prevents the DATA input from floating when the cable is not connected to the board.
If the board implements other configuration schemes (configuration device or processor based), the pull-up resistor is not required. In these scenarios, the configuration device or processor should hold the DATA input at a valid TTL logic level.