Xilinx® ISE SecureIP SupportCategory : Simulation/VerificationAldec simulators support the SecureIP methodology of IP delivery implemented in Xilinx ISE tool. This option enables Aldec customers with VHDL only license to simulate SecureIP models without purchasing a separate Verilog license (which is required as these models leverage IEEE 1364-2005 encryption technology). In order to leverage this option, VHDL only customers must use the Xilinx Simulation Libraries coming with the installation of Active-HDL or Riviera-PRO, or download them from Aldec website.