Seasoned embedded systems engineers and product developers in the electronics industry should be familiar with the functional differences between a microcontroller and a microprocessor. Both types of components are essential for designing and building various types of electronic devices, yet it can be difficult to distinguish between them based on their definitions alone:
A microcontroller is a small computer on a single integrated circuit chip. A microcontroller typically contains one or more processor cores, along with additional peripherals (memory, serial interface, timer, programmable I/O peripherals, etc.) on the same chip.
A microprocessor is a computer processor that incorporates the functions of a central processing unit (CPU) onto just a few (and often only one) integrated circuits.
On the surface, it seems like microcontrollers and microprocessors have a lot in common. They are both examples of single-chip processors that have helped accelerate the proliferation of computing technology by increasing the reliability and reducing the cost of processing power. They are both single-chip integrated circuits that execute computing logic, and both types of processors are found inside millions of electronic devices around the world.
To help clarify the differences between microcontrollers and microprocessors, we've created this blog post comparing the two most common types of computer processors. We'll look at every difference between a microcontroller and microprocessor, from architecture to applications, helping you arrive at a clear understanding of which of these components should power your next computer engineering project.
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The type of computer processor that you choose for your embedded system or computer engineering project will have a significant impact on your design choices and project outcomes, so it is crucial that you are fully informed about the main options and their unique features and benefits. Let's take a more detailed look at the difference between a microcontroller and a microprocessor.
Microprocessor and Microcontroller Architecture Explained
Microprocessors and microcontrollers perform relatively similar functions, but if we look specifically at the architecture of each type of chip, we'll see just how different they are.
The defining characteristic of a microcontroller is that it incorporates all of the necessary computing components onto a single chip. The CPU, memory, interrupt controls, timer, serial ports, bus controls, I/O peripheral ports, and any other necessary components are all present on the same chip and no external circuits are required.
In contrast, a microprocessor consists of a CPU and several supporting chips that supply the memory, serial interface, inputs and outputs, timers, and other necessary components. Many sources indicate that the terms "microprocessor" and "CPU" are essentially synonymous, but you may also come across microprocessor architectural diagrams that depict the CPU as a component of the microprocessor. You can think of a microprocessor as a single integrated circuit chip that contains a CPU. That chip can connect to other external peripherals such as a control bus or data bus that provide binary data inputs and receive outputs from the microprocessor (also in binary).
The key difference here is that microcontrollers are self-contained. All of the necessary computing peripherals are internal to the chip, where microprocessors deal with external peripherals. As we'll soon see, each of these architectures has its own unique advantages and disadvantages.
Microprocessor and Microcontroller Applications Explained
Microprocessors and microcontrollers are both ways of implementing CPUs in computing. So far we've learned that microcontrollers integrate the CPU onto the chip with several other peripherals, while a microprocessor consists of a CPU with wired connections to other supporting chips. While there may be some overlap, microprocessors and microcontrollers have relatively separate and distinct applications.
Microprocessors depend on interfacing a number of additional chips to form a microcomputer system. They are often used in personal computers where users require powerful, high-speed processors with versatile capabilities that support a range of computing applications. The use of external peripherals with microprocessors means that components can be upgraded easily - for example, a user might replace their RAM chip to benefit from additional memory.
Programmable microcontrollers contain all of the components of a microcomputer system on a single chip that runs at low power and performs a dedicated operation. Microcontrollers are most commonly used in embedded systems applications where devices are expected to execute basic functions reliably and without human interference for extended periods of time.
Three Key Differences Between Microcontrollers and Microprocessors
Cost
Generally speaking, microcontrollers tend to cost less than microprocessors. Microprocessors are typically manufactured for use with more expensive devices that will leverage external peripherals to drive performance. They are also significantly more complex, as they are meant to perform a variety of computational tasks while microcontrollers usually perform a dedicated function. This is another reason why microprocessors require a robust external memory source - to support more complex computational tasks.
With a microcontroller, engineers write and compile the code intended for the specific application and upload it into the microcontroller, which internally houses all of the necessary computing features and components to execute the code. Due to their narrow individual applications, microcontrollers frequently require less memory, less computing power, and less overall complexity than microprocessors, hence the lower cost.
Speed
When it comes to overall clock speed, there is a significant difference between industry-leading microprocessor chips and high-quality microcontrollers. This relates back to the idea that microcontrollers are meant to handle a specific task or application, while a microprocessor is meant for more complex, robust, and unpredictable computing tasks.
One of the key design advantages associated with microcontrollers is that they can be optimized to run the code for a specific task. That means using just the right amount of speed and power to get the job done - no more and no less. As a result, many microprocessors are clocking speeds of up to 4 GHz while microcontrollers can operate with much lower speeds of 200 MHz or less.
At the same time, the close proximity of on-chip components can help microcontrollers perform functions quickly despite their slower clock speed. Microprocessors can sometimes operate more slowly because of their dependence on communicating with external peripherals.
Power Consumption
One of the key advantages associated with microcontrollers is their low power consumption. A computer processor that performs a dedicated task requires less speed, and therefore less power, than a processor with robust computational capacity. Power consumption plays an important role in implementation design: a processor that consumes a lot of power may need to be plugged in or supported by an external power supply, whereas a processor that consumes limited power could be powered for a long time by just a small battery.
For tasks that require low computational power, it can be much more cost effective to implement a microcontroller versus a microprocessor that consumes much more power for the same output.
Embedded Systems and Microcontrollers
Microcontrollers include many features that make them suitable for application in embedded systems:
- They are self-contained, including all of the necessary peripherals on a single integrated circuit chip
- They are designed to run a single dedicated application
- They can be optimized (software and hardware) for a single dedicated application
- They exhibit low power consumption and may include power-saving features, making them ideal for applications that require the processor to function for long periods of time without human interference
- They are relatively inexpensive when compared to CPUs, mainly because the entire system exists on a single chip
While microprocessors may be more powerful, that additional power comes at a cost that makes microprocessors less desirable for embedded systems applications: larger size, more power consumption, and greater cost.
Summary
Ultimately, microcontrollers and microprocessors are different ways of organizing and optimizing a computing system based on a CPU. While a microcontroller puts the CPU and all peripherals onto the same chip, a microprocessor houses a more powerful CPU on a single chip that connects to external peripherals. Microcontrollers are optimized to perform a dedicated low-power application - ideal for embedded systems - while microprocessors are more useful for general computing applications that require more complex and versatile computing operations.
If you're an embedded systems engineer working on a new project with programmable microcontrollers, Total Phase has the tools that work for you and your embedded systems. From host adapters to protocol analyzers, we can help you save time and energy while debugging your product and reduce your overall time to market.
Any questions? Send them our way! You can reach out to us at sales@totalphase.com.