Marvell - 用于摄像头和车载显示的高效以太网物理层功能研究

Power efficient Ethernet PHY features for camera and display

Amir Bar-Niv

George Zimmerman

Paul Langner

IEEE Automotive Tech Day

September 2019

Contributors

•Saied Benyamin •Ramin Farjadrad

The Path Towards Full Autonomy

Level 1-2

Simple Aid

2010 -2015

2015 -2020

2020 -2025

CPU/GPU

Local Computing ”Behind” Every Sensor

Centralized Computing Integrates Input From All Sensors (Sensor Fusion ) Similar to a Human Driver’s Brain

High-Performance Brain

High-Speed, Reliable & Secure Nervous System Compute Power (TFLOPS)0.1

101100Networking Speed (Gbit/s)

0.1

10

1

25

Level 2-3

Decision Assistant

Level 4-5

Self Driving

Cameras

Increasing resolution from 720p to 4K and improving dynamic range

Multi-Gigabit/s of raw bandwidth

=

Sensor Fusion & Rich Data Drive Bandwidth To Multi-Gig

Sensor Fusion

Moving processing of data from sensors to a centralized GPU

Multi-Gigabit/s data over the network

=

GPU

In-Vehicle-Network (IVN) for ADAS

Ethernet Advantages for Automotive

•Standard based. Multiple vendors.

•Switching, VLAN: IEEE 802.1

•MAC Speeds: 2.5G, 5G, 10G, 25G, 50Gbps (soon 100G)•Security: IEEE-802.1AE MACsec plus Encryption (AES-256)•Synchronization: IEEE-1588v2 PTP (802.1AS and Rev)

•Power over Data Line: IEEE PoDL802.3bu (0.5W to 50W)•Audio/Video Bridging: AVB/TSN

•Support all topologies: point-to-point, mesh, star, ring, daisy-chain,

System backbone GPU GPU

GPU System backbone

ECU ECU ECU ECU

GPU GPU ECU GPU GPU

System backbone

Multi-Gig Eth.

Sensor backbone

Ethernet vs. LVDS

LVDS Ethernet

Speed3G, 6G, 12Gbps 2.5G, 5G, 10G, 25Gbps

Bit Error Rate (BER)10^-1010^-12

Switching (standard based)None IEEE –Dynamic,packet based Synchronization (standard based)None IEEE –1588 PTP

Prioritization (standard based)None IEEE–AVB, TSN

MAC/PHY Security (standard based)None IEEE –802.1AE

Bridges to Ethernet Required IEEE –Part of the stack

For camera/sensor interface, the main advantage of LVDS today is that it is asymmetrical, which is lower power then symmetrical mode.

Ethernet can leverage the Energy Efficient Ethernet (EEE) mode to ran the PHY in asymmetrical mode, for power saving.

IEEE Energy Efficient Ethernet -Overview

•Energy Efficient Ethernet (EEE) was introduced in BASE-T PHYs to help computers meet Energy Star power consumptions targets

•Basic idea is to turn the link off as much as possible when there is no traffic, and turn it on as quickly as possible when there is traffic (50 us)

•State is referred to as Low-power Idle (LPI)

•EEE allows:

•Up to 90% power savings on a link in LPI state

•Full flexibility in BW versus power consumption

•The ability to use a standard MAC/PHY interface, as EEE is also standardized on

these interfaces