面向112 Gbps PAM4串行接收机的低误码协同自适应均衡器

A low BER cooperative-adaptive-equalizerfor 112 Gbps PAM4 wireline receivers

高速串行接口是高性能计算机和数据中心芯片之间互连的核心关键IP。随着业界单通道速率由56 Gbps向112 Gbps发展,高速串行接口的误码率急剧增加,严重影响互连性能和系统稳定性。针对112 Gbps PAM4接收机误码率高的难题,首次采取一种协同自适应均衡器构架,提出了面向3种均衡器的自适应协同均衡算法,能在高插入损耗条件下取得较低误码率;提出了基于判决反馈均衡器的盲自适应均衡算法,能缩短链路训练时间,减少硬件开销。采用12 nm CMOS工艺完成了基于协同自适应均衡器的接收机设计。仿真结果表明,针对经过36.5 dB信道的去加重112 Gbps PAM4信号,采取协同自适应均衡器的接收机误码率小于1e^(-12),收敛周期约400 ns,功耗增幅仅约2.3%。

High speed serial interface is the key intellectual property(IP)for the inter-chip interconnection during the high performance computers and data centers.As the single-channel rate of the serial interface evolves from 56 Gbps to 112 Gbps,the high speed serial interface faces a sharp increase in the bit error rate(BER),which seriously affects the interconnection performance and the system stability.In order to solve the problem of the high bit error rate at 112 Gbps PAM4 receiver,a cooperative adaptive equalizer is proposed in this paper.Firstly,an adaptive cooperative equalization algorithm for three kinds of equalizers is proposed to achieve low bit error under the condition of large insertion losses.Then the blind adaptive equalization algorithm based on decision feedback equalizer is proposed to shorten the link training time and reduce the hardware overhead.This paper completes the circuit implementation of the receiver with the cooperative adaptive equalizer under the 12 nm CMOS technology.The simulation results show that the receiver with the proposed cooperative adaptive equalizer can steadily receive the 112 Gbps PAM4 signal under 36.5 dB condition with the BER less than 1e^(-12).It also can achieve the convergence period of about 400 ns and a power consumption increase of only about 2.3%.