VHDL modeling and simulation for a digital target imaging architecture for multiple large targets generation

Abstract

The subject of this thesis is to model and verify the correctness of the architecture of the Digital Image Synthesizer (DIS). The DIS, a system-on-a-chip, is especially useful as a counter-targeting repeater. It synthesizes the characteristic echo signature of a pre-selected target. The VHDL description of the DIS architecture was exported from Tanner S-Edit, modified, and simulated. Different software oriented verification approaches were researched and a White-box approach to functional verification was adopted. An algorithm based on the hardware functionality was developed to compare expected and simulated results. Initially, the architecture of one Range Bin Modulator was exported. Modifications to the VHDL source code included modeling of the behavior of the NFET and P-FET transistors as well as Ground and Vdd (the voltages connected to the drains of the FETs). It also included renaming of entities to comply with VHDL naming conventions. Simulation results were compared to manual calculations and Matlab programs to verify the architecture. The procedure was repeated for the architecture of an Eight-Range Bin Modulator with equally successful results. VHDL was then used to create a super class of a 32-Range Bin Modulator. Test vectors developed in Matlab were used to yet again verify correct functionality.