Optimizing interconnects, fanouts and signal structures before schematic capture.
As printed circuit boards (PCBs) grow denser, faster and more power-constrained, designers face mounting challenges maintaining signal integrity, power efficiency and manufacturability. Traditionally, most optimization occurs after schematic capture – during placement and routing – when it’s often too late to remove structural inefficiencies.
A new logic-level approach directly impacts board-level performance and complexity. By optimizing interconnects, fanouts and signal structures before schematic capture, a new gate-level synthesis technology enables PCB designers to start with a cleaner, more efficient foundation.
As modern PCBs continue to scale, wire area and wire delay have become dominant factors in overall circuit performance – often more critical than the logic gates themselves. Both wire quantity and wire length contribute significantly to propagation delay, crosstalk risk and power loss.
The aforementioned gate-level synthesis technology, GT Synthesis, addresses these PCB critical problems at the synthesis stage rather than leaving them to board layout. For example, swapping connections so a LUT-6 is driven by nearby LUT outputs instead of distant primary inputs yields shorter, lighter routing. It reduces high-fan-out nets that complicate PCB layout.
Similarly, larger LUTs with more inputs increase delay and power; the new technology automatically minimizes LUT input usage to lower power and simplify downstream routing.
High fan-out of circuit inputs often leads to excessive buffering and signal replication – both of which increase power, heat and routing congestion. The technology minimizes fan-out early, helping PCB designers avoid those physical penalties later.
Expanding PCB-Relevant Optimization Parameters
Typical LUT-6 benchmarks evaluate only the number of LUTs and logic levels. The novel technology introduces parameters that directly matter to PCB engineers:
- Total number of wires
- Number of input-connected wires
- Total number of LUT input pins
- Maximum fan-out for circuit inputs and LUT outputs.
By reducing these quantities during synthesis, the resulting hardware is simpler to route, more thermally efficient and electrically cleaner.
Conventional logic synthesis follows a multistage process:
- RTL conversion to Boolean functions
- Technology-independent optimization
- Mapping to standard cells
- Post-mapping optimization
- Test logic insertion.
The novel platform replaces this multi-step chain with a single unified synthesis phase built on its core innovation, called the GT Decomposition Method.
This method outperforms classical techniques such as the Ashenhurst-Curtis (Roth-Karp) decomposition by enabling direct generation of a final gate-level netlist in a single step. By intelligently varying parameters and constraints, it dynamically adapts circuit generation to meet specific performance, power and area goals.
It optimizes across parameters that have a direct PCB impact:
- Performance (delay)
- Power consumption
- Total area
- Gate count
- Total wire count
- Input-connected wire count
- Number of gate inputs
- Maximum fan-out and logic level.
Supporting standard gates (AND, OR, NAND, NOR, XOR, AOI) and LUT-6 structures, the novel technology can generate thousands of optimized netlists for a single truth table, providing designers with greater control and flexibility.
Case Study
The novel technology demonstrates measurable benefits that directly translate into PCB design. Figure 1 shows an ALU control unit (EPFL Benchmark 2024). Figure 2 shows the version synthesized with GTs. Structural improvements of the latter include:
- Swapped 20 of 123 connections so LUT-6 inputs are driven by other LUT outputs (local connections)
- Reduced total wire count: 148 → 128 (−13.5%)
- Cut fanout on five of seven FPGA primary inputs: 22 → 15 (−31.8%)
- Reduced FPGA primary-input connected wires: 119 → 70 (−41.1%).
Measured impact benefits include:
- Power: ~9% lower (range 6–14%)
- Speed (Fmax): ~12–18% higher when critical nets are affected; 7–11% otherwise
- Area: No die shrink, but ~1–3% fewer logic resources due to reduced buffering and replication.
Figure 1. Benchmark arithmetic logic unit.
Figure 2. ALU synthesized with GTs.
These logic-level improvements simplified downstream PCB routing and reduced input congestion – all before schematic capture.
Fewer Wires, Lower Power
Each logic-level optimization directly translates into a simpler, cleaner PCB design.
Fewer components result in a smaller PCB. Reducing gate count and consolidating logic decreases the number of discrete devices or FPGA resources required. This leads to fewer packages, lower pin counts and reduced routing congestion – yielding smaller, more cost-effective boards.
Fewer connections simplify routing. GT Synthesis minimizes wire and connection counts, which means fewer traces and shorter total wire lengths. This simplifies routing, improves signal integrity and reduces crosstalk, especially critical in high-speed, high-density designs.
Lower power means easier thermal design. By optimizing switching activity, GTs lowers power consumption at the logic level.
Better timing results in fewer signal integrity issues. Through fanout reduction and minimized logic depth, balanced signal timing and shorter critical paths are possible. As a result, designers could spend less time compensating for propagation delays or matching trace lengths on the board.
Additionally, GTs can generate testable circuits during synthesis, eliminating the need for separate test-logic insertion. Test vectors are created automatically, speeding validation. A unified testing architecture enables multiple subcircuits to share a single testing framework, reducing hardware overhead.
Visualization and security are built in. All synthesis data – including truth tables, libraries, constraints and results – are stored locally for data security.
Smarter Logic, Simpler PCBs
As electronic systems scale in complexity, the link between logic synthesis and PCB design grows stronger. The novel technology enables engineers to address performance, power and area early for cleaner, more efficient circuits that are easier to implement, verify and manufacture.
In short, smarter logic means simpler boards.
George Toms, Ph.D. is founder of GT Synthesis (gtsynt.com). He an expert in ASIC synthesis for efficient PPA, static timing analysis, scripting, netlist optimization, software data structures, Boolean algebra, digital circuit design, software integration and internationalization, algorithm optimization, and more, he has master's and doctoral degrees in mathematical cybernetics from Tomsk State University; This email address is being protected from spambots. You need JavaScript enabled to view it..
