Practical Programmable Circuits

The vehicles that are used to implement the design solutions can take a variety of shapes. On one end of the spectrum are the programmable logic devices (PLDs). These are integrated circuits (ICs) with a collection of logic gates that are electronically wired together under software control. Somewhere in the middle of the spectrum are state machines. These circuits make use of programmable read only memories (PROMs) (or PLDs) and latches to provide a very orthogonal environment for executing sequential logic functions. At the high end of the spectrum are microcontrollers. Microcontrollers are small computers fabricated on a single IC. These computers can be programmed, often in ways similar to their full size cousins, to accomplish a wide variety of logic and control functions