July 4, 2024
Programmable Silicon

Unlocking Innovation: The Evolution of Programmable Silicon in Computing

The evolution of silicon-based computing over the past few decades has been remarkable. From static logic to programmable logic and processors, silicon has transformed entire industries and societies. As we move towards an increasingly digital and connected world, programmable silicon will play a bigger role in shaping technology in novel and innovative ways.

The Rise of Programmable Logic

While processors have driven a major part of computing innovation, programmable logic has also evolved significantly. In the early days, programmable logic devices such as PALs (Programmable Array Logic) and PLAs (Programmable Logic Arrays) provided basic logic functions that could be customized. However, their flexibility was very limited compared to today’s highly complex FPGAs (Field Programmable Gate Arrays).

FPGAs can contain millions of logic elements, memory blocks, DSP slices and I/O pins whose functions and interconnections can be programmed post-manufacturing. This allows designing and testing sophisticated digital circuits and systems without the need for an Application-Specific Integrated Circuit (ASIC) fabrication cycle. Over the last few decades, FPGAs have become the preferred choice for hardware acceleration, signal processing, embedded systems and rapid prototyping. The SRAM-based Programmable Silicon logic in FPGAs can be reconfigured easily, enabling applications in domains such as communications, automotive, consumer devices and healthcare.

Evolving Programmable Accelerators

While general purpose processors will continue powering software applications, the growing demand for AI, machine learning and data analytics is driving the development of specialized programmable hardware accelerators. Such accelerators utilize programmable logic to implement domain-specific functions with high throughput and efficiency. Examples include Nvidia’s TPU pods for AI training, Intel FPGAs for machine learning inference and Xilinx Alveo accelerators for financial analytics.

Some key features that are influencing the evolution of programmable accelerators include:
Vector Processing Engines: Dedicated hardware units for processing large vectors/matrices as needed by neural networks, genomic sequencing etc.
Integrated Memory: On-chip high bandwidth memory (HBM, DDR etc.) to avoid bottlenecks between processors and external memory.
Reconfigurability: Ability to reprogram hardware kernels depending on changing algorithm and data types.
Highly Parallel Architecture: Multiple processing elements that can be configured for parallel execution models.
Open Programming Models: Support for languages such as Python, C/C++ or frameworks like TensorFlow, Pytorch etc to lower programming effort.
Packaging & Scalability: New form factors leveraging technologies like 2.5D/3D packaging for seamless scaling of compute and memory.

Custom Computing Systems

As FPGAs and programmable accelerators get more powerful, complex and domain-optimized, they will increasingly be used as building blocks for designing custom computing systems. One can envision purpose-built solutions optimized for workloads in specialized domains like computational imaging, molecular dynamics simulation, autonomous systems and more.

Such custom systems will combine programmable logic, parallel processing elements, copious on-chip memory and RTL-programmability with novel interconnect and packaging technologies. They can match or even surpass general purpose CPUs and GPUs in performance and efficiency while being customized for the target application domain. Promising examples include the DNA nanotechnology research system ‘ODIN’ from Anthropic and cloud-optimized BrainChip Akida product family for low-power neural network acceleration.

Open Source Programmable Silicon Projects

Open source projects are democratizing programmable silicon by enabling users to design their own System-on-Chips (SoCs) without significant barriers. One such initiative is RISC-V which promotes open instruction set architectures that can be implemented on various silicon platforms including FPGAs. Several SoC designs based on RISC-V exist in development boards from SiFive, Anthropic etc which can run full-fledged operating systems.

Another notable project is Chisel – an open source hardware construction language under Apache 2.0 license from UC Berkeley. Chisel helps designing complete digital circuits and mapping them to various programmable silicon technologies. Several Chisel-based SoC designs are available as open source hardware projects on GitHub. Such open hardware initiatives encourage innovation while expanding the creativity and opportunities with programmable silicon platforms.

Augmenting General Purpose Processors

Finally, programmable logic will keep augmenting general purpose processors rather than fully replacing them. Hybrid computing platforms that seamlessly integrate programmable logic fabric, parallel accelerators and conventional processor cores are gaining traction. Processors will continue focusing on optimizing for complex workloads while offloading hardware-accelerated functions to programmable fabrics.

One example is Intel’s new Harpertown Itanium processor which features PCIe links to connect FPGAs. FPGAs act as customizable co-processors, accelerating functions like cryptography, signal processing, data compression etc. Multi-chip modules with this heterogeneous processor-FPGA architecture promise significant performance/watt gains compared to CPU-only systems. Such hybrid models exemplify the emerging role of programmable silicon in modern computing architectures.

The programmability and flexibility offered by silicon is revolutionizing computing. FPGAs, accelerators, custom systems and open hardware initiatives are expanding the capabilities of digital circuits and systems. Heterogeneous computing platforms that seamlessly integrate programmable logic, processors and novel packaging technologies promise to unlock new levels of performance and efficiency. As software continues its relentless march forward, programmable silicon will remain an indispensable building block fuelling innovation for years to come.

*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it.