Microprocessor vs Microcontroller: What's the Difference?

Microprocessor vs Microcontroller – is a microprocessor the same as a microcontroller? Both terms have been used interchangeably with each other over the years, and in some cases, might confuse users.

Both microprocessors and microcontrollers are designed for real-time computing applications, and indeed they share many similar features. However, there are also very significant differences between the two in both conceptual and application levels.

In this guide, we will make explicitly clear the key differentiation between microprocessors and microcontrollers, their applications, and also some popular microcontroller and microprocessor products like the Raspberry Pi, Beagleboard Black, and Arduino.

What Is a Microprocessor?

In a nutshell, a microprocessor is an integrated circuit (IC) that is responsible for performing the necessary tasks and instructions of computer processing.

All computers must have at least one microprocessor, that acts as the central unit that manages and executes all the logical tasks and instructions.

Physically, a microprocessor is a multi-purpose silicon chip that takes binary data as the input, processing this data, and then produces data output according to the instructions/programs stored in the memory.

A microprocessor is composed of integrated circuits that can contain thousands or more transistors. The more transistors it contains within the system, the more powerful the computing capability is.

We can most certainly say that a microprocessor is the most important element of any computer. Without it, the computer simply can’t do its function.

A microprocessor’s task is to execute computational and logical operations such as addition, subtraction, multiplication, inter-processes, device communications, input/output management, and so on.

Key Takeaway: a microprocessor is something small (micro) that processes data, instructions, and tasks (processor)

What Is a Microcontroller?

A microcontroller is a compact circuit that is designed to control or govern specific operations in an embedded system — a combination of hardware and software that is designed for specific functions, mainly as a part of a larger system.

A microcontroller typically consists of a microprocessor, i/o (input/output) devices, and memory on a single chip. We can say that a microcontroller is a computer on its own that is only able to do specific tasks (most often, only one specific task).

Compare this with our laptop, for example, that is a “general-purpose computer” that can run thousands of different programs. Most commonly the microcontroller can only do one specific program that is stored in the ROM (Read Only Memory) that is also integrated within the microcontroller system.

Generally, we can’t change this program. Microcontrollers are typically embedded inside another device, so it can control specific actions of the device. This is why a microcontroller is often called “embedded controller”.

Differences of Microprocessor vs Microcontroller

After we’ve discussed the basic definitions of microprocessors and microcontrollers, we can see that they are very different from each other and the terms shouldn’t be used interchangeably. To discuss further, here are some notable differences between a microcontroller and microprocessor:

A microprocessor only consists of a processor unit, while a microcontroller can include other peripherals like RAM, ROM, EEPROM, I/O devices, and more that are integrated into just one microcontroller chip.
Typically a microcontroller is smaller (only a very small chip), while a microprocessor tends to be bulkier and more complex.
A microprocessor is typically much more expensive than a microcontroller. A microcontroller is mostly made from metal oxide semiconductor materials that are cheaper compared to silicon-based materials used in microprocessors.
The average speed of microcontrollers is only about 8MHz to 50MHz, while for microprocessors it can be about 1GHz and even well above 3GHZ. Speed-wise, a microprocessor is much faster.
A microcontroller typically has a smaller power consumption compared to a microprocessor, and often equipped with a power-saving mode (or idle mode). A microprocessor can’t be idle at all times, and there are various external devices that must run altogether with the microprocessor for it to perform accurately.
Tasks and instructions executed by a microcontroller are generally simpler without any complex structures, while in microprocessors, the tasks can be very complex.
Microprocessors are based on the von Neumann architecture model where both programs and data are stored within the same memory module. On the other hand, microcontrollers are based on Harvard architecture where data memory and program memory are separate.

Applications of Microprocessor vs Microcontroller

Microprocessor Applications

We can virtually find at least one microprocessor in any device we used daily nowadays: desktop PCs, laptops, tablets, and even your smartphone. However, here is a breakdown of important microprocessor applications in various industries:

In Computers
- As established, microprocessors are the brain of any computer unit from microcomputers and single-board computers (SBCs) to supercomputers
- Nowadays, mobile devices like smartphones or tablets also rely on microprocessors to execute instructions
- Smart TVs, game consoles, VCRs also use microprocessors to execute complex computations and various other tasks
In Household Appliances
- Smart appliances and devices like a smart thermostat, smart doorbell, and smart security camera all employ sensors that are controlled by at least one microprocessor. A smart camera, for example, has a microprocessor that works together with motion and sound sensors, as well as the camera itself to record and display video footage.
- Premium refrigerators, washing machines, coffee makers, and other similar appliances also contain a microprocessor.
Transportation Industry
- Modern vehicles and public transportation use a microprocessor technology, for example, to access GPS systems, regulate its function, and so on.
Health Industry
- Various medical devices are controlled by microprocessors to perform various purposes like collecting information from biosensors, analyzing health information from patients, and storing data.

Microcontroller Applications

Various devices and appliances rely on microcontrollers to perform specific operations, such as:

Consumer appliances: any automatic home appliances like microwave, washing machine, etc., also in children’s toys and cameras
Medical instruments: ECG, Accu-check, etc
Measurement instruments: multimeter, current tester, oscilloscopes, etc.
Communication devices: smartphones, answering machines, telephone, fax, etc.
Automotive and transportation: speedometer, ABS system, etc.
Other equipment: MP3 player, printer, PDAs, etc.

Is the Raspberry Pi a Microcontroller?

It’s a common misconception to call the popular Raspberry Pi a microcontroller (and in some cases, some people might mistake it as a microprocessor). However, technically the Raspberry Pi is NOT a microcontroller, but rather it’s more accurate to call it a single-board computer or small board computer (SBC).

What Is an SBC?

In a layman’s term, a single board computer is a complete computer that is built on just one circuit board. It is a completely self-contained or embedded computer that is designed differently from standard general-purpose computers and can integrate more than one microprocessor, memory units, and input/output (I/O) peripherals.

An SBC is significantly different from a microcontroller mainly due to how an SBC is able to execute more than one or two specific operations and act more like a general-purpose computer. An SBC, however, can also perform as a microcontroller to control or govern specific functions when needed.

Below, we will discuss some of the popular SBCs available in the market today, their unique advantages and disadvantages, and key facts you might want to know.

Raspberry Pi 4

The Raspberry Pi 4 is arguably one of the most popular single-board computers available today, mainly due to its versatility, fairly complete set of features, and surprisingly powerful capabilities.

Also, Raspberry Pi 4 is among the easiest to use compared to other SBCs and has a fairly shallow learning curve. This is also due to Raspberry Pi’s huge community with hundreds of projects available, from simple ones like smart mirrors, to very complex ones like tablets and even functional robots.

Key Specifications

Quad-core 1.5GHz Arm Cortex-A72 CPU
VideoCore VI GPU
Broadcom BCM2711 System
1/2/4 GB LPDDR4 RAM
11ac Wi-Fi / Bluetooth 5.0, Gigabit Ethernet connectivity
2 x micro-HDMI ports supporting 4K@60Hz displays via HDMI 2.0, MIPI DSI display port, MIPI CSI camera port, 4 pole stereo output, and composite video port
2 x USB 3.0, 2 x USB 2.0
40-pin GPIO header for expandability
5V/3A via USB-C, 5V via GPIO header power output

If you want to learn more about how to use Raspberry Pi 4 in your project, we’d recommend Exploring Raspberry Pi: Interfacing to the Real World by Derek Molloy as your starting point.

I am a big fan of Derek’s books because he takes an engineering first approach rather than a recipe or hobby type one.

Beagleboard BeagleBone Black

The BeagleBone Black is admittedly a relatively new SBC among its competitors and is originally developed as a low-cost, high I/O count SBC. Because of the sheer number of I/O points and raw power of this board, I simply love it!

Key Specifications

AM335x 1GHz ARM® Cortex-A8 processor
512MB DDR3 RAM
4GB 8-bit eMMC onboard flash storage
3D graphics accelerator
NEON floating-point accelerator
2x PRU 32-bit microcontrollers
USB client for power & communications
USB host, Ethernet, HDMI connectivity
2x 46 pin headers for expandability

I’d recommend Exploring BeagleBone: Tools and Techniques, again written by Derek Molloy, if you want to learn more about BeagleBone SBCs — and especially BeagleBone Black.

Arduino Mega 2560

Arduino and Raspberry Pi are often confused with each other for several reasons. Both of them are two of the most popular SBCs available today, they both began in as affordable budget hardware and STEM education, and they performed very similarly to each other.

However, they are actually very different from each other in architecture level.

Arduino is based on microcontrollers, while a Raspberry Pi is actually a microprocessor integrated with on-board RAM and other peripherals.

Arduino is arguably easier to use than Raspberry Pi in building electronic prototypes, but the Pi is more versatile and can be used as a full desktop computer.

Key Specifications

ATMega 2560 microcontroller
5V operating voltage
7-12 V recommended input voltage, 6-20 V lower and upper limits
54 digital I/O pins, including 15 pins with PWM output
16 analog input pins
20 mA DC current per I/O Pin
50 mA DC current for 3.3V pin
256 KB Flash memory, 8KB SRAM, $KB EEPROM
16 MHz Clock Speed
13 LEDs
52 mm L x 53.3 mm W
37 grams

If you want to learn further about using Arduino in building your electronic projects, I’d recommend Exploring Arduino: Tools and Techniques for Engineering Wizardry, because of Jeremy Blum’s engineering first approach.

Conclusion

As we can see, there are some core differences between microcontrollers and microprocessors from their main concepts to applications. Also, we have also learned that single-board computers (SBCs) can be based on microcontrollers (the Arduino) and can be mainly a microprocessor (the Raspberry Pi).

A microcontroller is typically far cheaper than a microprocessor, but at the same time is usually only designed for one specific purpose. On the other hand, a microprocessor is more general-purpose and can power a full-range desktop computer on its own.

However, the microprocessor needs external peripherals like I/O devices, RAM, ROM, and so on, while these devices are usually built-in and integrated with a microprocessor chip.

Final Words…

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