Digital Systems Design and Prototyping: Using Field Programmable Logic and Hardware Description Languages, Second Edition covers the subject of digital systems design using two important technologies: Field Programmable Logic Devices (FPLDs) and Hardware Description Languages (HDLs). These two technologies are combined to aid in the design, prototyping, and implementation of a whole range of digital systems from very simple ones replacing traditional glue logic to very complex ones customized as the applications require. Three HDLs are presented: VHDL and Verilog, the widely used standard languages, and the proprietary Altera HDL (AHDL.