The term microcontroller means an integrated circuit with a specialized microprocessor that meets two basic criteria:

• is capable of autonomous operation, i.e. in the simplest applications it does not require the connection of external auxiliary systems, e.g. memory;
• was designed to work in control and measurement systems, so it has an extensive communication system with the environment, both using digital and analog signals.

A standard microprocessor consists of a central unit and residual data memory in the form of a set of registers. Most microprocessors also contain a clock generator. Microprocessors, however, do not have built-in program memory, input/output systems or peripheral systems.

Therefore, a microcontroller can be considered, at first approximation, as a microprocessor with additionally built-in memory systems and systems for communicating with the environment. An important difference also concerns the set of operations performed by the CPU, called the instruction list. In the case of microprocessors, the instruction list is designed to facilitate numerical calculations and data transmission, while microcontrollers have extensive groups of instructions to operate peripheral devices.

The SU 1.2 driver and the SU 1.5 driver use 8-bit RISC microcontrollers from ATMEL.