DESIGN AND ANALYSIS OF A DIGITALLY CALIBRATED MULTILANE SERDES ARCHITECTURE FOR ULTRA-HIGH-SPEED VLSI INTERCONNECTS

Abstract

Ultra-high-speed VLSI interconnects have become a critical enabler for modern computing and communication platforms, where serial data rates have rapidly scaled from a few gigabits per second to beyond 56–112 Gb/s per lane, and aggregated multi-lane links routinely exceed 400 Gb/s in contemporary systems. At the same time, interconnect power can account for 20–40% of total chip I/O power, making energy-efficient and scalable Serializer/Deserializer (SerDes) architectures a key research challenge. Traditional single-lane digitally controlled SerDes architectures, while effective at moderate speeds, face inherent problems at ultra-high data rates, including high power consumption and jitter sensitivity due to Phased Lock Loops (PLL)/ Clock and Data Recovery (CDR) blocks, as well as increased area, calibration complexity, and latency caused by independent clock recovery and equalizer adaptation. To address these limitations, this work proposes a digitally calibrated multi-lane SerDes extension architecture that scales throughput by parallelizing multiple lanes while maintaining signal integrity and timing robustness. A shared hierarchical digital PLL and low-skew clock distribution network synchronizes all transmit lanes, while per-lane programmable Finite Impulse Response (FIR) based transmitter equalizers and hybrid Continuous-Time Linear Equalizer with Decision Feedback Equalizer (CTLE–DFE) receiver equalizers with digital adaptation compensate for lane-specific channel impairments. At the receiver, per-lane digital CDRs with phase interpolators are combined with an elastic buffer–based lane bonding and deskew unit to correct inter-lane skew and ensure aligned data boundaries. A centralized digital calibration and control engine continuously monitors phase offsets, delay mismatches, and error metrics, dynamically tuning clock phases and equalizer coefficients. It enables linear throughput scaling with controlled power and area overhead, making the architecture well-suited for next-generation ultra-high-speed VLSI interconnect standards