How microchips work

The System Level

The system level is an abstraction where the CPU is not viewed from the inside with all the control systems and functional units, but it is simplified and visualized as a complete and finite device with certain functionalities and characteristics. What is relevant on this level of abstraction is the device's input / output requirements including power supply and clock, its operating behavior including instructions that the device can understand and execute, performance limitations, its temperature range, package requirements, and others. This simplification helps system designers to focus on their wider design specifications without getting lost in a simple IC's details.