ABSTRACT
The invention and development of microcontrollers relates closely to the evolution of embedded systems. All embedded systems contain a microcontroller although some systems also include other digital components that provide specialized functionality. For example, an embedded system that deals in Real-Time units will typically include a Real-Time clock IC such as the NJU6355, which will furnish this functionality. Real-time or reactive computing refers to systems that are subject to a time constraint. By definition, a real-time computing system is one that interacts with the real world or that has timing requirements related to this interaction. In general, the response of a Real-Time system must take place within a specific time frame. Real-Time systems are often classified as hard and soft. Systems that must meet strict timing requirements are classified as hard while those in which there is a more flexible tolerance of the timing requirement are soft Real-Time Systems.
