We describe a RASSP-based design methodology for application specific signal processing systems
which supports reengineering and upgrading of legacy systems using a virtual prototyping design
process. The VHSIC Hardware Description Language (VHDL)  is used throughout the process
for the following reasons. One, it is an IEEE standard with continual updates and improvements;
two, it has the ability to describe systems and circuits atmultiple abstraction levels; three, it is suitable
for synthesis as well as simulation; and four, it is capable of documenting systems in an executable
form throughout the design process....