There exists a very thin line between hardware and software. When creating hardware for gadgets such as computers, you must ensure that it runs and executes code.
Field Programmable Gate Array (FPGA) is a hardware architecture form that allows users to customize circuits from any place and at any time.
Learning about how FPGA programming works will be valuable if you want to pursue a career in computer science or technology.
In this article, we shall describe what FPGA programming is, how it works, and where it is applied, and share various resources to shed more light on it.
FPGA Programming
An FPGA is an integrated circuit (IC) with configurable logic blocks and an assortment of other features that can be programmed and reprogrammed by the user.
The phrase ‘field programmable’ indicates the FPGA’s abilities are not hardwired but adjustable. Users can thus modify the circuit’s functions anytime to meet their specific design intentions.
FPGA programming can be described as the process of creating computing solutions using FPGA.
The programmer has to plan, design, and execute the gates’ architecture to create a functional circuit that meets the users’ needs. The end goal of FPGA programming is to create a hardware circuit that generates specific output when powered on.
The circuit boards on an FPGA are designed to mimic the behavior of real-world circuits. Such circuit boards are thus most used by the quality assurance team to test new products. An FPGA system will have various hardware elements.
The logic gates act as the FPGA’s building blocks at the basic level. The logic gates perform Boolean operations on input and output data. There are also routing resources that route signals from one point to another.
Use Cases of FPGA programming
FPGA programming has become very attractive to developers in the modern world.
The following are some of the use cases;
#1. Designing ASICs
Developers can now design application-specific integrated circuits (ASICs). ASICs have become very popular in the world of Bitcoin mining.
The design of FPGA makes it easy to correct errors. The beauty of an FPGA is that you can use one as a model for other projects and thus save time and resources in the long run.
#2. Renewable energy sector
Renewable energy from wind and solar is becoming more popular in a world facing the global warming challenge. Transmission and distribution (T&D) substations require efficient power networks for the smart grids to perform optimally.
FPGAs are very useful in improving the scalability and performance of smart grids while still maintaining low power consumption.
#3. Aerospace and defense
Planes sometimes fly through harsh environments. Manufacturing companies thus produce rad-hard and rad-tolerant FPGAs that offer more reliability, performance, and lifecycle demands of extreme environments than traditional ASIC implementations.
#4. Server applications
Data centers/ servers have become a thing as demand for data processing speed increases with each passing day. Data needs to be processed in real-time, even under limited space and time constraints.
FPGA, through BRAM, can offer connectivity to external data storage elements, accelerating data processing on chips.
Benefits of FPGA Programming
- FPGAs are Reconfigurable. The usability of FGPAs must be considered. You can configure one and reconfigure it to be used in another application.
- FGPA requires less manual intervention. The software handles routing, timing, and placement tasks in an FGPA environment. Such tasks can be time-consuming and complex if handled manually.
- FPGAs come as blank canvases. Unlike traditional ASICs with predefined functionalities, FPGAs can be reprogrammed for different use cases. An engineer can thus program such a system to different use cases using HDLs (Hardware Design Language).
- Prototyping. ASICs are expensive to manufacture, and a simple mistake can be very costly. Before you release your ASIC to the market, it is important to ensure that your system is functional and meets the goals it was designed for. FPGAs are reprogrammable, meaning you can test runs until you get the design right.
How to Program an FPGA
The designs used to run FPGAs are primarily coded in Hardware Description Languages (HDL) such as SystemVerilog, Verilog, and VHDL.
#1. Verilog
Verilog is ideal if you want to program FPGAs within a few lines of code. This language is comparable to C even though it is designed for hardware architecture. Verilog was created to make HDL more flexible and robust.
#2. SystemVerilog
SystemVerilog was created as Verilog’s extension. It is both a hardware verification and hardware description language. With this language, you can describe hardware patterns, convert them into digital code, and then upload them into an FPGA system to perform specified tasks.
#3. VHDL
VHDL is the short form for Very High-Speed Integrated Circuit Hardware Description Language. With VHDL, you can describe an FPGA’s hardware, allowing users to model and simulate it before they encode it into the actual hardware.
Programming with VHDL makes it easy to determine potential errors in the circuit that users can fix before final encoding. VHDL allows users to write their structured code.
High-Level Synthesis (HLS), where the design is done in a subset of C, and the compiler transforms the code into Verilog code, is popular with developers who want to program FPGAs.
Developers can thus use the languages they are conversant with to design FPGAs through unified software platforms.
#4. Python
This multipurpose programming language can be used to program FPGAs. To achieve this, Python uses PYNQ, an open-source project that makes it easy to work with AMD platforms.
#5. C and C
C-based languages are ideal for FPGA design due to the high-level synthesis (HLS). The AMD Vivado™ HLS compiler offers a programming environment sharing key technologies with specialized and standard processors, which optimizes C-based programs.
#6. AI platforms like TensorFlow and PyTorch
Engineers use trained deep-learning models from Pytorch or Tensorflow to compile for FPGA acceleration. Such an approach eliminates the need for low-level hardware programming while still achieving blazing-fast compilation.
Code written in normal programming languages, such as Python, C, or C , is synthesized and converted into proprietary interconnect descriptions through synthesis tools.
The resultant file containing the interconnect description is known as the bitstream. A bitstream describes how to configure an FPGA (how to connect flip-flops, gates, and various digital circuit elements via the interconnect matrix of the FPGA).
FPGAs have an inbuilt configuration that reads the bitstream file and accordingly configures FPGA. The configuration circuit can read the bitstream file through various approaches, such as Parallel Flash Memory, JTAG, and Serial Flash Memory.
FPGA board manufacturers provide software/ instructions developers use to configure/ program the systems.
Most FPGA systems can be reprogrammed as many times as possible. The only limitation is when such systems are damaged by out-of-spec conditions such as wear and tear, temperature or high voltage.
You can learn more about FPGA programming through these Learning Resources
Learning Resources
#1. FPGA Programming for Beginners
This book introduces you to the world of FPGA programming using SystemVerilog. The teaching approach is project-based, where you develop real-world applications such as a keyboard and a calculator.
The book introduces the FPGA architecture before exploring how to write SystemVerilog RTL. This book also introduces you to computer math basics, pipelining, and parallelism. The book also touches on advanced topics such as AXI and keyboard interfacing with PS/2.
This book is ideal for programmers, engineers, and embedded system developers who desire to learn FPGA and SystemVerilog programming. This resource is also suitable for FPGA designers who thirst for hands-on experience creating real-world projects.
#2. FPGAs for Software Programmers
This book introduces software engineers to the world of FPGAs and reconfigurable technology. The book starts by introducing FPGA and its programming model. This is also the book to use if you want to learn how FPGAs implement various applications without low-level hardware design processes.
The book gives a realistic sense of problems that suit FPGAs and how to implement solutions from a software engineer’s point of view. The user-oriented approach in this book makes it easy to understand where FPGA technology is applicable and how. The target readers of this book are software designers and FPGA design engineers.
#3. Beginning FPGA: Programming Metal
This book teaches readers how to use BeMicro MAX 10 to build a temperature sensor, motion sensor, temperature sensor, and KITT car display from Knight Rider. The book is beginner-friendly and suitable for those without programming skills or an electronics engineering degree.
The book introduces FPGAs and explains their differences from microcontrollers or ASICs. It is also the resource to introduce you to how to set up a toolchain and use VHDL to program the FPGA. The book is ideal for electronics and Raspberry Pi enthusiasts who want a hands-on introduction to the world of FPGAs.
#4. Programming FPGAs: Getting Started with Verilog
This book is perfect if you have never interacted with Verilog and FPGAs. If FPGA programming is a new term to you, this is a good place to get started. The typical samples, such as counters and 7-segment displays, will get learners on the right foot.
The book introduces learners to Verilog and offers various intermediate examples like VGA. This resource may not be ideal if you already have Verilog and FPGAs knowledge. This book is available in Kindle and Paperback versions.
Conclusion
FPGAs can, at times, perform better than GPUs in deep learning applications with low latency. FPGA programming is an essential skill as FPGA can be used in consumer electronics, industrial automation, and military applications, among many other applications. FPGAs are still evolving, and we can only wait to see them fine-tuned for more use cases and better performance.
