FPGA vs Microcontroller: Which One Is Better?

What Is an FPGA?

Close-up view of the electronic circuit

FPGA is an acronym for field-programmable gate array. An engineer can program this piece of hardware to perform specific tasks. 

FPGAs are useful in a wide range of applications. You can find them in high-end audio and industrial equipment where processing speed isn’t required, but programming customization is necessary. 

FPGA applications aren’t limited to industrial uses, however. They’re also valuable for consumer electronics like cell phones, televisions, and video game consoles like the PlayStation 5, which utilizes custom FPGAs for graphics processing.

Unlike ASICs and CPUs, FPGAs are not optimized for any task and are reprogrammable as needed. The level of customization possible with an FPGA makes it a flexible tool for many different uses. 

Pros

• FPGAs have programmable hardware, which you can modify to program new hardware or logical functions by changing the programmable blocks.
• FPGAs process instructions in parallel, allowing you to control interrupts using Finite State Machines (FSMs).
• You can use the trial and error method in FPGA, which allows a steep learning curve.

Cons

• It can be challenging to configure an FPGA as the engineer has to compile all the codes from scratch to convert them into machine language.
• Creating an application may not utilize all blocks, resulting in high power consumption. FPGA consumes more power than a Microcontroller or an ASIC.
• FPGAs can be expensive and bulky for simple applications.

What Is a Microcontroller?

Man debugging an electronic PCB device. 

A microcontroller is a small computer on a single integrated circuit (IC). It’s a type of embedded system, meaning it’s not a standalone computer. It applies to many applications, including industrial control, consumer electronics, and automobiles. It consists of a processor, memory, and programmable input/output peripherals on the same chip. 

While a microprocessor has its separate memory (RAM) and can perform general-purpose computing tasks such as running an operating system, microcontrollers are useful for dedicated functions such as motor control.

Microcontrollers are also helpful in smartphones and tablets, which help control the device’s operation. You can use them to control devices that require more computation than a simple circuit but not as much as a full-blown computer.

Pros

• Microcontrollers are more accessible to the program
• Microcontrollers are more suitable for simple hardware applications.
• Microcontrollers are less expensive 

Cons

• Microcontrollers are limited in how they function because they have a limited instruction set. 
• Depending on the firmware loaded into the controller, the controller can only perform preloaded instructions.
• Microcontrollers rely on sequential processing, meaning programming using interrupts (ISR) can become complex.

How Do They Work?

FPGAs are configurable logic blocks, small pieces of hardware that you can use to perform various functions. The FPGA can be programmed to perform these functions by loading a configuration bitstream onto the FPGA. When these logic blocks combine into larger units, they perform more complex tasks.

Microcontrollers are different in that they have a limited number of built-in logic blocks, which you can use for specific tasks (such as adding two numbers together). A CPU then executes instructions that control how these logic blocks interact with each other. 

Microcontrollers usually have a small amount of memory, but some have additional external memory for storing programs or data.

How Are They Similar?

FPGAs and microcontrollers are recommended as part of a more extensive system. You can program them in high-level languages such as VHDL or Verilog.

In addition, most FPGAs support some form of memory interface, allowing them to access external memory devices such as flash memory or SRAM chips through an I/O bus interface.

Differences Between FPGA and Microcontroller

Picture of different circuit boards

Power Consumption

FPGAs are more power efficient than microcontrollers because they are reconfigurable. This allows them to use less energy even when they’re not in use. Microcontrollers do not have the same level of reconfigurability as FPGAs, so they must constantly run even when doing nothing.

FPGA vs. Microcontroller Cost

One of the main differences between FPGA and microcontrollers is the cost. While both have their advantages, FPGAs are more expensive than microcontrollers.

The cost difference is because FPGAs are more complex. They have more logic cells, RAM, ROM, and other components to perform specific tasks within a circuit or system.

High Data Volumes

FPGAs are good at handling high data volumes, especially when you need to process real-time video or audio streams.

Microcontrollers, on the other hand, are good at taking low data volumes. You can use them for sensor readings and other small tasks that don’t require high performance.

Reliability

FPGAs are more reliable than microcontrollers because they have a higher error tolerance. This means that if there is an error in the design, you can correct it before the chip is ready for use. Microcontrollers do not have this capability, so if there is an error in your plan, you will get a non-functional board.

FPGAs have multiple power supplies for different parts of the chip. This allows them to operate at lower voltages than MCUs and increases their reliability in harsh environments.

FPGAs have many built-in features (such as memory) that MCUs do not have, making them less susceptible to errors like single-point failures or simple crashes due to bugs in software.

FPGA vs. Microcontroller Comparison Table

Choosing Between FPGA and Microcontroller

Electronic components on a modern PC

You can use FPGAs and microcontrollers at different times; one isn’t better than the other. It depends on your project’s requirements as they have different qualities you can take advantage of in different situations. 

It’s always best to use the most straightforward tool for your project, and if you can get away with using a microcontroller, do it. If you think you need FPGAs, that’s OK, but you need to know the advantages and disadvantages. 

FAQs

FPGA vs Microcontroller: Is FPGA Better Than Microcontrollers?

The answer is it depends on what your needs are. They are more reliable than microcontrollers because they have a higher error tolerance but tend to cost more than microcontrollers. So it all depends on your project needs.

FPGA vs Microcontroller: Is Arduino Microcontroller or FPGA?

The Arduino is a microcontroller board that works on the ATmega32U4. This microcontroller has a USB interface, making it easy to program and upload sketches. 

Is FPGA a Microcontroller or a Microprocessor?

It’s neither. FPGAs are programmable devices. You can program them to perform a wide variety of tasks and functions. FPGAs are alternatives to microcontrollers and microprocessors because they are more flexible, robust, and efficient.

Summary

FPGA and microcontrollers are essential components required for building an embedded system. They differ in function, so it’s best to figure out your specific project needs before making a choice.

If you have any questions about whether they are the right fit for your needs, feel free to contact us or leave a comment below.