Optimizing RTL-Based FPGA Designs for ECU Performance Enhancement: Impact of Hierarchical Flattening Using Xilinx Vivado
Pulimi Mahesh, M Suresh Chinnapamthy, M Parthiban, Rr Rajarajavigraman, Suhaib Akthar, S Yeswanth · 2025
A Performance, Low-Power, and Optimized FPGA Design for Real-Time Processing in Automotive Applications for Functional Safety of Electronic Control Units (ECUs) Project: The impact of hierarchical flattening on RTL designs synthesized through XILINX VIVADO for ECU optimization Structured design techniques provide advantages such as modularity, legibility, and reuse but can incur increased latency and resource overhead. Hierarchical flattening removes module bounds, allowing aggressive optimization at the cost of modularity. We analyzed three levels of flattening (None, Rebuilt, Full) to see their effects on synthesis time, area utilization, power efficiency and timing performance. The work includes hardware validation on FPGA board, Power and Timing analysis using Vivado tools such as report_power, report_timing_summary for hierarchical vs flattened designs. The results show that flattening decreases power consumption by up to 10% and synthesis time and area usage by 20% and 15%, respectively, therefore making the optimization strategy suitable for ECU. Aggressive flattening though can result in timing violations and makes debugging difficult. This is the best synthesis strategy presented here that gives the FPGA designers an option to balance performance and modularity, thereby allowing efficient ECU design.