It is important to preserve the VHDL package file sequence if your VHDL package files are interdependent.
To specify the VHDL package file order:
From the Options menu, choose Package File Organization. The VHDL Package Files dialog box appears.
Use the up and down arrows to specify the order, or drag the files into order.
Select Simulation or Synthesis if you want the file included when simulation or synthesis is run.
Click OK.