Unused Inputs to Primitives, Megafunctions and Macrofunctions

The following rules apply to unconnected input ports on primitive, Intel^® FPGA IP, and macrofunction symbols and instances.

• Unused inputs to flipflop primitives have the following defaults:

  CLRN:		VCC (inactive)
  PRN:		VCC (inactive)
  ENA:		VCC (active)

  The data and clock inputs to flipflops and the data and ENA inputs to latches are required.

• An unused OE input to a TRI buffer defaults to VCC (active, output enabled).
• Unused inputs to logic primitives in Block Editor files must be connected to VCC or GND.
• The default logic levels for unused inputs to Intel^® FPGA IP, if any, are documented in the Help for each Intel^® FPGA IP. There may not be a default input to some ports on Intel^® FPGA IP, and failure to connect such ports causes the Compiler to issue error messages.