The Role of the Infinite Loop
One of the most fundamental differences between programs developed for embedded systems and those written for other computer platforms is that the embedded programs almost always have an infinite loop. Typically, this loop surrounds a significant part of the program’s functionality, as it does in the Blinking LED program. The infinite loop is necessary because the embedded software’s job is never done. It is intended to be run until either the world comes to an end or the board is reset, whichever happens first.
In addition, most embedded systems run only one piece of software. Although hardware is important, the system is not a digital watch or a cellular phone or a microwave oven without that software. If the software stops running, the hardware is rendered useless. So the functional parts of an embedded program are almost always surrounded by an infinite loop that ensures that they will run forever.
If we had forgotten the infinite loop in the Blinking LED program, the LED would have simply changed state once.