Don t miss a bit! The importance of built-in system diagnostic tools for Ethernet Physical Layer transceivers

Transcription

1 Don t miss a bit! The importance of built-in system diagnostic tools for Ethernet Physical Layer transceivers 1

2 Ethernet Training summary: The training will be focused around Automotive Ethernet and PHY level diagnostic tools. The presentation will briefly summarize why Ethernet is widely adopted in automotive networks. The diagnostic tool functions of TI Ethernet PHYs is discussed, as well as why the tools are important, how they are used, and where they can add the most value to a system. What you ll learn: Concepts related to Automotive Ethernet diagnostic tools: SQI, TDR, temp monitor, BIST, error counters, and more. Course Details: Type: Presentation and demonstration Format: PowerPoint Duration: 45 min Language: English Cost: Free Target Audience: Systems, HW Design Engineers and System Integrators 2

3 Agenda Automotive Ethernet Overview Why use PHY level tools? What are the tools and how are they used? Live Demo Q&A 3

4 AUTOMOTIVE ETHERNET 4

5 Why Ethernet in Automotive The car of the future is changing dramatically: The number of Hybrid and Electrical cars is increasing Data exchange between a car and the environment gets more important ( V2X, real-time traffic information real time parking slot detection etc. The cars a prepared for the different levels of autonomous driving 5

6 Software update and end of Line Programming Rapidly increasing software in ECU s The importance to get the time for e/o Line programming down The requirement for frequent software updates 6

7 Why Ethernet in Automotive (Summary) These Trends lead to the following topics, which require factor 10 to 100 of data rate supported by traditional in car networks like CAN and Flexray Software update and End of Line Programming Online Maintenance Change of processing topology ( from distributed to central ) Connected Car and real-time services Enhanced sensors with tremendously increasing data rate ( Headlight, camera, radar,. ) 7

8 TI Design TIDA Automotive Stand-Alone Gateway Reference Design with Ethernet and CAN Visit: ti.com/tool/tida Description This reference design targets automotive gateways with a focus on increasing bandwidth and processing power in gateway applications. The design implements Ethernet physical layer transceivers (PHYs) for increased bandwidth along with an automotive processor for greater processing capabilities allowing automotive gateways to pass more data at higher speeds. Furthermore, the design offers a starting point for a full automotive gateway design with a full power tree, CAN PHYs, and components selected with automotive requirements and emission specifications in mind to simplify the design process. Features IEEE802.3bw 100BASE-T1 Automotive Ethernet PHY IEEE802.3u 100BASE-TX Ethernet PHY CAN PHY Designed to Operate Through Cold Crank, Jump Start, and Load Dump Reduced EMI Power Stages 8

9 TI Design TIDEP-0097 Cost-Effective In-Vehicle Infotainment System Visit: ti.com/tool/tidep-0097 Description This automotive reference design is based on TI s Jacinto DRA71x processor and focuses on system level cost savings.. The sixlayer design reduces PCB costs through optimized via breakout scheme and power distribution network as well as integration of key features. Functionality can be added or removed based on the end product requirements. This design targets applications such as infotainment and reconfigurable digital cluster. The design has a 12-V input with a single PMIC. The design supports HDMI, USB3.0 or USB2.0, TAS6424 digital Class-D amplifier, FPD-Link interface, and many other features. A Linux, Android, or QNX based software development kit (SDK) is included. Features Jacinto DRA71x Processor SDK for Linux, Android, and QNX Development With Add-on Packages for Radio and Audio IEEE802.3bw 100BASE-T1 Automotive Ethernet PHY 9

10 WHY DO I NEED PHY LEVEL TOOLS? 10

11 Diagnostic tool use case scenarios in automotive Testing Component evaluation During system characterization System validation Operation System startup, initial system check Periodic system checks during operation Signal monitoring Long term signal monitoring ( degradation ) Service/Maintenance/Production Get information on link quality and cable fault location 11

12 PHYSICAL LAYER DIAGNOSTIC TOOLS 12

13 SIGNAL QUALITY INDICATOR AND TIME DOMAIN REFLECTOMETRY 13

14 SQI Signal Quality Indication Signal Quality Indication works with an active link Based on SNR ( Signal-to-Noise Ratio ) Allows real-time channel health Monitoring of short term events Long-term monitoring for an early indication of signal degradation Interesting channel effects can be detected Adjacent channels Electrical transient events Effect of mechanical bending 14

15 SQI Deep Dive Inputs: Slicer error squared DSP initialization control Outputs 10*SNR in db SQS (3 bits) SQI (4 bits) Actions 2 20 Samples of squared slicer error Repeat ever ~15ms; continuous Squared error accumulated and then sum is divided by 2 20 and rounded off to get Mean Squared Error MSE(dB) = 10*log 10 MSE MSE(dB) = (10/log 2 10)*log 2 MSE SNR = (Eb*R)/(No*B) B = Bandwidth = MHz R = Bit Rate = 100 Mbps SNR(dB) = 10*log 10 (3*(Eb/No)) PAM3 Symbol Distribution P(+1) = 3/8; P(-1) = 3/8; P(0) = 2/8 15

16 SQI Deep Dive Es = 3/8 + 3/8 = 3/4 Eb = Es/log 2 M = 3/(4*log 2 3) No/2 = MSE No = 2*MSE SNR(dB) = 10*log 10 ((9/8)*(1/log 2 3)*(1/MSE)) SNR(dB) = - (10/log 2 10)*log 2 MSE

17 TDR Time Domain Reflectometry Method to test cable condition when link is down Proven technology in telecommunications, powerline and industrial Ethernet TDR is implemented in automotive Ethernet PHYs Pulse generator Peak detector Impedance discontinuity By measuring voltage amplitude, polarity, and time interval of the reflected pulse the nature and position of the fault can be determined. 17

18 Time Domain Reflectometry 100BASE-T1 MDI Filter Auto-Connector Fault Auto-Connector MDI Filter Link Partner ρ = Z L Z O Z L + Z O Distance = ν ρ T 2 Z O = Line Impedance Z L = Load Impedance ν ρ = velocity of propagation for the cable T = total transit time from pulse generation to fault condition and back 18

19 Which faults can be covered today 19

20 TEMPERATURE MONITORING 20

21 Grade 3 Areas of Temp Grade in a car Grade 1 Grade 0; -40 C+150 C Grade 1; -40 C+125 C Grade 2; -40 C+105 C Grade 3; -40 C+ 85 C Grade 2 Grade 3 Grade 3 Grade 1 Grade 0 21

22 Ambient and Junction Temp AEC-Q100 temp grades spec ambient temp (T A ) Junction temp is critical parameter for semiconductors (T J ) Junction temp is estimated using thermal resistances, power disp, ambient temp Complex Si devices can be difficult to rate Variable device power consumption based on use case can change ambient temp requirement Theta-JT Theta-TA Theta-JC Theta-CA Junction to Top of package Top of package to ambient Junction to case Case to ambient 22

23 DATA PATH TOOLS (BIST) 23

24 BIST - Built in Self-Test and loopback uc or processor Automotive Ethernet PHY Link partner PHY AFE X MII TX PRBS PCS DSP MAC M A C PHY X MII CHK PCS DSP RX CNT xmii Loopback PCS Loopback Digital Loopback Analog Loopback External Loopback 24

25 OTHER ERROR INDICATIONS 25

26 Counters and Logs RX_ER Counter Detection of code-group errors on the reception of packets from a link partner Detects corruption of the coding and sends notification to the MAC False Carrier Counter Detection of false start of frames If corruption on the line occurs, it can be viewed as the beginning of a frame Link Drop Counter Link-Up Timer FEC Counter Forward Error Correction is applicable to 1000BASE-T1 You can implement log of errors and even error corrections made PRBS Counter Used for debug and bring-up 26

27 THANK YOU! Diagnostic Tool Kit Video Link! 27

28 Q&A 28

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