Correct-By-Design Methodology Requires Carefully Defined Constraints

Since the dawn of PCB usage, constraints have been an important part of the design. What are the dimensions? What weight of copper? Now, constraints have become much more than just physical dimensions. The most important constraints are defined by the design requirements of differential pairs, BGAs, low voltage devices, and high-speed parallel interfaces. The cost of rework skyrockets the fu... » read more

Routing Closure Challenges At 28nm And Below

As I described in my last article, the gap between router tech files and signoff rule decks at 28 nm and below is generating some serious impacts on tapeout schedules. The mismatch between the router’s simplified tech file and the complex rules that represent the intricate manufacturing requirements at these leading-edge nodes means designs that come from the router “DRC/DFM-clean” will, ... » read more

Dealing With New Bottlenecks

By Ed Sperling While the number of options for improving efficiency and performance in designs continues to increase, the number of challenges in getting chips at advanced process nodes out the door is increasing, too. Thinner wires, routing congestion, more power domains, IP integration and lithography issues are conspiring to make design much more difficult than in the past. So why aren... » read more

Too Many Rules

By Ed Sperling The number of restrictive design rules that have to be dealt with by routers at 28nm and beyond has increased by several orders of magnitude compared with several generations ago, creating havoc in the automated tools world and slowing down the entire design process. At a time when market windows are shrinking, complexity is making it harder to meet even the old schedules. Th... » read more

Routing Congestion Returns

By Ed Sperling Routing congestion has returned with a vengeance to SoC design, fueled by the advent of more third-party IP, more memory, a variety of new features, as well as the inability to scale wires at the same rate as transistors. This is certainly not a foreign concept for IC design. The markets for place and route tools were driven largely by the need to automate this kind of operat... » read more