Happy New Year 2025: Crazy Times and MAD Clocks
A story about rails, standards, and a proposal to standardize low latency digital clock distribution for ICs
Dear Friends, as we wrapped up another remarkable year in semiconductor design, I'm excited to share something that could make at least one aspect of ASIC design less challenging. Our industry is reaching unprecedented levels of power density in integrated circuits, with foundry engineers creating groundbreaking innovations like "Backside Power" to feed these power-hungry beasts. In these demanding times, I'd like to share a solution I discovered years ago - a sweet spot for low latency clock distribution we call "PIX-EDA MAD Clocks." This engineering solution steps slightly off the beaten path, challenging conventional approaches where FEAR and GREED sometimes lead clock distribution designers astray. By consciously embracing certain design principles, MAD Clocks delivers remarkable benefits:
8x reduction in clock insertion delay
Significantly reduced power consumption through smaller matched driver size and clock trace capacitance
Reduced clock jitter through supply noise cancellation
Elimination of first harmonic clock driver demand currents in IC Power Integrity models
Avoid a potential gate oxide voltage overshoot reliability concern
What makes this approach unique is how it consciously works with, rather than against, physical realities like inductance and the skin effect. While our industry often ignores inductance in places where it shouldn't, MAD Clocks creates a safe operating region where timing models remain reliable while delivering superior performance. My holiday wish is to help pave the way toward a future where MAD Clocks are already considered in the toaster-scale ICs that will deploy Backside Power. I look forward to a time when we'll talk about "MAD Clocks inside"! Enjoy the holiday season, and here's to creating innovative solutions for our industry's challenges in the coming year.
Best wishes, Christian
Here the link to the video that I published on 12/24/2024 to explain the MAD Clocks proposal:
https://www.youtube.com/watch?v=bNRRr_Zt84k
