An Embedded system is a combination of computer hardware, software and perhaps additional parts,either mechanical or electronic-designed to perform a dedicated function. A good example is the microwave oven. Most of todays existing technical applications are controlled by so-called embedded systems,Many different application areas which demands their own specific embedded system architecture exist.
Very-large-scale integration (VLSI) is the process of creating an integrated circuit by combining thousands of transistors into a single chip. VLSI began in the 1970s when complex semiconductor and communication technologies were being developed. The microprocessor is a VLSI device. Before the introduction of VLSI technology most ICs had a limited set of functions they could perform. An electronic circuit might consist of a CPU, ROM, RAM and other glue logic. VLSI lets IC makers add all of these into one chip.