Modeling custom hardware in VHDL
This report focuses on models for describing Hardware at different refinement levels within High Level Synthesis flow: SFSMD, FSMD and FSM Controlling Datapath. Simple data interfaces are often needed in these models. The hardware description language VHDL is used and tested for implementing these models and interfaces. Problems inherent in the models as well as problems caused by VHDL are discussed. A model related main difficulty is the one-cycle delay of data processing, when introducing a datapath. VHDL descriptions of abstract models (SFSMD) can become complicated. Templates for general problems, examples and VHDL guidelines are provided in this report to help to minimize design errors significantly.