ABSTRACT
Embedded-system design and microprocessor history form a closely linked double helix. Without microprocessors, there would be no embedded systems because the very term “embedded” refers to the microprocessor(s) embedded inside of some electronic system that is clearly not a computer. Microprocessors coupled with soware or rmware allow system complexity with exibility in ways not possible before microprocessors existed. No other digital building block can as easily manage a windowed user interface or compute a complicated mathematical algorithm as soware or rmware running on a processor. e numerous limitations of the earliest microprocessors-including limited address spaces, narrow data buses, primitive stacks (or no stacks at all), and slow processing speeds-made them poor foundations for designing computer systems but designers have used microprocessors since their introduction to build increasingly complex embedded systems. Because
of their complexity, such systems would be impractical or impossible to make without the nimble rmware adaptability inherent in microprocessor-based design.
