ContractHIL-HLS Automates HLS Design with Hardware Feedback

A new multi-agent workflow, ContractHIL-HLS, has been introduced to streamline and enhance High-Level Synthesis (HLS) engineering. This system leverages a structured "contract" as a central artifact, which translates natural language requirements into explicit interfaces, constraints, validation checks, and rollback rules for hardware design. This contract ensures semantic alignment throughout the development process. A key innovation of ContractHIL-HLS is its integration of hardware-in-the-loop feedback. The system incorporates real-world data from HLS tools, Vivado, PYNQ runtime, power consumption, and failure evidence directly back into the design generation process. This extends LLM-assisted HLS beyond just kernel code, enabling system- and board-level closure. The workflow employs specialized agents: a Contract Agent for natural language translation, an HTML Agent for contract rendering, and a Hardware-in-the-Loop Agent for design implementation and revision based on measured evidence. Evaluations show significant improvements in testbench pass rates for small designs and substantial runtime reductions for complex applications like post-quantum cryptography accelerators, demonstrating its practical efficacy.