351 - How do the VCCIB pins on the LatticeECP3 need to be connected if the SERDES receive inputs (HDIN) are not being used?

351 - How do the VCCIB pins on the LatticeECP3 need to be connected if the SERDES receive inputs (HDIN) are not being used?

 If the SERDES receive input (HDIN) signals are not being used, you have the following options for connecting VCCIB:

  • The LatticeECP3 SERDES input block can be powered down. When the SERDES input logic is not powered it is not necessary to connect the VCCIB pins to a supply rail.  The VCCIB pins can be left floating.
  • The VCCIB pins do not require special filtering circuitry and can be tied directly to 1.2V if the receive logic is not used.

For more information on the LatticeECP3 SERDES, see the LatticeECP3 SERDES/PCS Usage Guide (TN1176).