New Method for FPGA HIL Testing
FPGA specialist Adam Taylor demonstrated a practical method for hardware-in-the-loop (HIL) testing using common FTDI chips. By connecting the chip via USB for JTAG/UART and to drive FPGA I/O, engineers can use Python scripts for automated GPIO stimulus and response checking without needing custom test hardware.
Hardware-in-the-Loop (HIL) testing traditionally creates a virtual environment for embedded systems, but it often relies on expensive, specialized platforms from companies like OPAL-RT or National Instruments. These systems can range from tens of thousands to millions of dollars, placing them out of reach for many smaller projects or individual developers. The key to this new, lower-cost method is a feature in FTDI chips called the Multi-Protocol Synchronous Serial Engine (MPSSE). This engine allows the chip to convert high-speed USB 2.0 (480Mbps) traffic into synchronous serial protocols like JTAG, SPI, or I2C, not just the more common UART signals. This versatility is what lets a common, off-the-shelf component replace bespoke test hardware. The use of Python for test automation is part of a larger industry trend moving verification to higher levels of abstraction than traditional HDLs. Open-source frameworks like `cocotb` allow engineers to write testbenches in Python, leveraging its extensive libraries and simplifying the creation of complex stimulus and checking routines compared to VHDL or Verilog. Adam Taylor, the expert behind this demonstration, has a significant background in developing high-reliability FPGA systems for the space, defense, and automotive industries. His experience includes roles as a Design Authority at Astrium Satellites (now Airbus Space) and Chief Engineer for a space imaging company, lending considerable weight to the practicality of his methods. This approach effectively democratizes HIL testing, enabling students and engineers to perform sophisticated verification for portfolio projects or early-stage prototypes. It lowers the barrier to entry by replacing high capital expenditure on dedicated test rigs with a low-cost FTDI chip and programming skills in a widely-used language. Integrating this type of script-based HIL setup into a Continuous Integration/Continuous Deployment (CI/CD) pipeline becomes much more feasible. Automated regression tests can run with every code change, allowing for the early detection of hardware-software integration bugs, a core practice in modern DevOps and crucial for complex systems in aerospace and robotics.
