A formal semantics for Verilog-VHDL simulation interoperability by abstract state machine

A formal semantic analysis for Verilog-HDL and VHDL is provided in order to give the simulation model especially focusing on signal scheduling and timing control mechanism. Our semantics is faithful to LRM and is expected to become a coherent first step for a future semantic interoperability analysis on multisemantic-domain such as Verilog-ARMS and VHDL-AMS. By ignoring the differences of the two simulation cycles, we can use the common semantic functions and the common simulation cycle.