TINA/Spice/UCC256304: - no model available to simulate new PSU design - please provide SPICE model

Part Number: UCC256304

Tool/software: TINA-TI or Spice Models

Dear Sir/Madam,

Please can I have a SPICE model for this component to aid in the design of a power supply?  The only model that I can find is an encrypted SIMPLIS model and I am unable to use it because the free version of SIMPLIS does not support use of encrypted models.  (SIMPLIS is not part of our standard suite of software and we do not design enough power supplies to warrant purchasing it.  We always design with SPICE and we have always obtained sufficient results using SPICE and it is an environment in which our development engineers are comfortable.  Therefore we have no interest in purchasing SIMPLIS.  If no SPICE model is available, the free version would be an option - but the encrypted models do not work in the free version)  Now I am left without any way to model the circuit...  Please help...  How can I model my power supply for which I would like to use TI's UCC256304 as the controller?

Best regards,