Lecture on FPGAs (Field Programmable Gate Arrays)

Introduction

• Speaker: Prakash Iyer
• Background: Three decades in the computing industry, mainly at Intel
  • Focused on computing, mobile devices, Big Data
• Purpose: Discussion on FPGAs, their building blocks, programming, and applications.

Overview of FPGAs

• Definition: FPGAs are programmable electronic devices that can be configured to perform specific tasks.
• History: Invented in the mid-80s, have rapidly evolved, and are used in diverse applications.
• Applications: Medical imaging, factory automation, AI speech recognition, broadband cellular networks.
• Unique Feature: Can be reprogrammed to change functionality even after deployment.

Basic Building Blocks of FPGAs

• Digital Logic Design: Foundation for building modern chips using:
  • Logic Gates: AND, OR, NOT
  • Use of DeMorgan’s Theorem: All digital circuits can be built using these gates.
• Key Components:
  • Clock: Regulates timing by rising and falling at set frequencies (e.g., MHz, GHz)
  • Flipflop: Storage device that captures input during clock transition, holds output until next transition.

Creating Functions with Logic Gates

• Binary Addition: Example of a simple logic function using gates.
  • Carry Bit: Used when addition overflows (1 + 1 = 0, carry 1).
• Application to ASICs (Application-Specific Integrated Circuits):
  • Custom-built chips: Fast and efficient but costly and inflexible.
  • FPGA Advantage: Reprogrammable and cost-effective for mid-volume applications.

FPGA Architecture

• Lookup Tables (LUTs): Basic component for logic functions.
  • LUT Masks: Populated with output values for logic inputs.
  • Adaptive Logic Modules (ALMs): Combine LUTs and flipflops for complex functions.
• Programmable Routing and Interconnect: Flexible routing of data, albeit slower than ASICs.
• Modern Enhancements:
  • Memory Blocks: On-chip memory for data storage.
  • DSPs: Enhance computational power for math-intensive tasks.
  • CPU Subsystems: Integrated CPUs for additional processing capability.
  • Programmable IOs: Broad connectivity for varied applications.

FPGA Programming

• Languages: VHDL and Verilog for hardware design.
• High-Level Abstraction: Data parallel C++ and oneAPI for easier programming.
• Application Areas: Real-time IoT, network security, wireless networks, AI.

Future of FPGAs

• Trends: Increasingly used in AI, flexible to evolving technology protocols.
• FPGA vs ASICs: FPGAs are versatile and adaptable; ASICs are designed for long-term, high-value markets.
• Evolution: As technology evolves, FPGAs continue to add functionality and find new applications.

Conclusion

• FPGAs are a crucial technology in modern electronics, offering flexibility and adaptability in a rapidly changing landscape.