Hardware description languages
It is straightforward to represent simple digital circuits using logic diagrams like the ones presented earlier in this chapter. When designing digital devices that are substantially more complex, however, the use of logic diagrams quickly becomes unwieldy. As an alternative to the logic diagram, several hardware description languages have been developed over the years. This evolution has been encouraged by Moore’s law, which drives digital system designers to continually find new ways to quickly make the most effective use of the constantly growing number of transistors available in integrated circuits.
Hardware description languages are not the exclusive province of digital designers at semiconductor companies; even hobbyists can acquire and use these powerful tools at an affordable cost. Some are even free.
A gate array is a logic device containing many logic elements such as NAND gates and D flip-flops that can be connected to form...