The single most important event in the electronics field was the creation of integrated circuits, which made miniaturization possible and led to the development of microprocessor and microcontrollers. These two types of electronic chips drive the working of almost every 'smart' electronic device, ranging from machine tools, cell phones to modern laptop computers. While both offer automated control of devices, they differ substantially in their internal structure, functions and overall applications. In this Buzzle article, I present a microprocessor vs microcontroller comparison that highlight the differences between the two electronic chips.
What is a Microprocessor?
A microprocessor is an integrated chip designed to process binary data fed to it, according to the programming instructions stored in its memory, to function as a central processing unit. It is a clock driven circuit which can be programmed to accomplish multiple tasks. Greater the number of transistors, higher is its processing ability. For a microprocessor to function, it needs to be connected with external memory (RAM) and input output ports. They are versatile devices which can be programmed in higher level computing languages to accomplish a wide range of functions.
A computer processor is an example of a high-end microprocessor with billions of transistors etched on a single chip, to handle all the processing tasks of a digital computer. Depending on how program memory and data memory is accessed, it can be differentiated into Princeton (Von Neumann) and Harvard architectures. Microprocessors are classified according to the number of bits they can process at a time. They range from 8 bit chips to 64 bit chips used in computers. They have the capability of executing a vast instruction set.
What is a Microcontroller?
A microcontroller is an integrated circuit like a microprocessor, with its own memory and input out ports. Designed to be embedded into smart appliances and gadgets, they have precompiled machine code stored on their inbuilt memory module, which is executed according to the specific inputs fed into them. Data and programs are typically stored on them using EEPROM, ROM, EPROM or flash memory. Since these processors don't use external memory, they have a very limited instruction set, that also limits their applicability. Such a device has several input and output pins which are used to gain information from external sources and provide an appropriate response accordingly, in real time.
They are designed to provide real time automated functionality in appliances, ranging from cell phones, printers, cranes, washing machines to every other automated machine imaginable. Because of its inbuilt memory and input output ports, a microcontroller is a compact device which can be deployed without the need for much external circuitry. In short, they are ready to be deployed, pre-programmed processors used in embedded systems.
Microprocessor Vs. Microcontroller Comparison
A microcontroller is a self contained processor with on-board memory and peripherals designed with a small instruction set, designed to run automated electronic devices, while a microprocessor is a chip with high transistor density, designed to carry out a range of complex processing functions with a much wider instruction set; used to drive full scale computers.
While micrcontrollers are geared towards usage in embedded systems, microprocessors are primarily used in computing machines which execute programs written in higher level languages. A microprocessor needs external memory and connections with input output ports to function, while microcontrollers have all these peripherals on board, which makes their operation substantially fast compared to microprocessors. While a microcontroller may achieve higher speed in operation, it's functionality is limited by its small instruction set.
Most importantly, microprocessors of higher complexity, like the x86 family of computer processors are programmable and can therefore execute a wide variety of functions, compared to microcontrollers which are designed to execute very specific and limited tasks.