SNLA435A September 2023 – January 2024 DS320PR1601 , DS320PR410 , DS320PR810
This application note describes the Texas Instruments PCI Express Gen5.0 linear redriver family’s Eye Scan feature functionality. The intended audience for this document includes hardware engineers using Texas Instruments PCI-Express Gen5.0 linear redrivers, including DS320PR410, DS320PR810, and DS320PR1601. Eye Scan is intended to be used as a supplemental vertical eye quality monitoring tool. Eye Scan's convenience, low run-time, and non-invasive nature are beneficial when performing PCIe redriver tuning.
All trademarks are the property of their respective owners.
PCI-Express (PCIe) is a high-speed serial computer expansion bus standard common to desktop and server motherboards as an interface to graphics cards, network interface cards, hard disk drives, solid state drives, and various other hardware connections. When designing a motherboard or riser card for PCIe where the PCB’s high-speed traces or connecting cable’s insertion loss exceeds the maximum PCIe insertion loss requirement (36dB at PCIe Gen5.0, 32GT/s), a linear redriver can be used to compensate for added inter-symbol interference (ISI) induced by added insertion loss on these interconnect mediums. Texas Instruments PCIe Gen5.0 linear redrivers deploy continuous time linear equalizers (CTLE) on their receivers to provide a programmable high-frequency boost. This is followed by a linear output driver, creating a linear data path to preserve transmit preset signal characteristics while staying transparent to PCIe link training.
This application note describes the Texas Instruments PCIe Gen5.0 redrivers Eye Scan feature, which provides additional insight into vertical eye quality at the redriver’s transmitter output pins. This document includes details on the Eye Scan feature capabilities and real-world examples of Eye Scan results.