High Speed Serial Data Link Analysis ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

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High Speed Serial Data Link Analysis 2010 ANSYS,

2 Agenda High-Speed Signal Data Path Simulation Requirements Ansoft HSSD Analysis Solution 3 Steps to Analysis HSSD Performance Step 1: Build the channel Step 2: Check Frequency Domain Performance Step 3: Check Time Domain Performance Demonstration 2010 ANSYS, Inc. All rights reserved. 2 ANSYS, Inc. Proprietary

High-speed serial system design Evaluate

transmitter and a receiver 2010 ANSYS, Inc.

4 High-Speed Signal Path High-Speed Signal Path Discontinuities will distort signal quality and reduce overall bandwidth of the system Tx + + path + + Rcv ANSYS, Inc. All rights reserved. 4 ANSYS, Inc. Proprietary

representation of the electrical characteristics of very

6 Simulation Requirements Components must be modeled using full-wave S-parameters S-parameters provide the best representation of the electrical characteristics of very high-speed interconnects ANSYS, Inc. All rights reserved. 6 ANSYS, Inc. Proprietary

AEYEPROBE(required) ANSOFT Simulation Requirements Simulator must provide reliability and

Maintaining passivity and causality Address multiple channel paths Combine transistor-level

Ansoft LLC 1.00E+000 1.00E-001 1.00E-002 1.00E-003 1.00E-004 1.00E-005 1.00E-006 1.00E-007 1.

00E-014 BER Bathtub Nexxim1 Curve Info fcutoff='300mhz' fcutoff='325mhz' fcutoff='350mhz'

7 AEYEPROBE(required) ANSOFT Simulation Requirements Simulator must provide reliability and capacity for multi-gigabit channel modeling Including S-parameters in transient simulations Maintaining passivity and causality Address multiple channel paths Combine transistor-level models of transceivers, pre-emphasis circuits and equalizers with extracted full-wave parasitics. Ansoft LLC 1.00E E E E E E E E E E E E E E E-014 BER Bathtub Nexxim1 Curve Info fcutoff='300mhz' fcutoff='325mhz' fcutoff='350mhz' fcutoff='375mhz' fcutoff='400mhz' 1.00E UnitInterval 2010 ANSYS, Inc. All rights reserved. 7 ANSYS, Inc. Proprietary

Simulation Requirements GHz designs must include

predict system performance High-performance

specifications in the time domain and in the

8 Simulation Requirements GHz designs must include frequency- and-time domain simulations to correctly predict system performance High-performance electronic designs often include operating specifications in the time domain and in the frequency domain ANSYS, Inc. All rights reserved. 8 ANSYS, Inc. Proprietary

Ansoft HSSD Analysis Solution 2010 ANSYS, Inc.

10 IC/Package/Board Simulation HFSS TM, SIwave TM, DesignerSI TM and Nexxim Tools overview HFSS TM : general purpose full-wave 3D extraction SIwave TM : full-wave extraction of merged Package and Board model DesignerSI TM : schematic level design integration and management, transient simulation using S-Parameters with simulation accuracy, capacity, and speed with consistency across frequency- and time-domains ANSYS, Inc. All rights reserved. 10 ANSYS, Inc. Proprietary

12 Why is HFSS the Accepted Industry Standard for Accuracy? The mesh is automatically created and adapted for accuracy. Create Initial Mesh Solve fields using the Finite Element Method Generate New Mesh Max( DS )<goal? no Calculate local Solution error yes Calculate broad band s-parameters (if desired) 2010 ANSYS, Inc. All rights reserved. 12 ANSYS, Inc. Proprietary

13 SIwave What is SIwave? Hybrid 2.5D full wave EM field solver Models layered structures Analyses performed Signal Integrity Power Integrity Electromagnetic Compatibility/Interference 2010 ANSYS, Inc. All rights reserved. 13 ANSYS, Inc. Proprietary

2D Extractor 2D field solver within it 2D Extractor A Must

prelayout SI design) Creates Tabular W- elements Industry

Parametrics Optimization Sensitivity Statistical Tuning

14 2D Extractor 2D field solver within it 2D Extractor A Must have for transmission line modeling (key requirement for prelayout SI design) Creates Tabular W- elements Industry Golden Standard Parameterize with ease Analysis suite Parametrics Optimization Sensitivity Statistical Tuning Different thickness 2010 ANSYS, Inc. All rights reserved. 14 ANSYS, Inc. Proprietary

Ansoft Designer Design Management Framework Fully Integrated Design Environment Schematic & Layout Time and

with HFSS, SIwave, Q3D, 2D Extractor Import data from a variety of sources Spice netlists, S-parameters, W-elements

such as SSN, SSO, TDR, BER and eye diagrams QuickEye TM and VerifEye TM Fast convolution and statistical eye

16 Ansoft Designer Design Management Framework Fully Integrated Design Environment Schematic & Layout Time and frequency domain circuit simulator Component Libraries and Design Kits True Co-Simulation thanks to Dynamic Links with HFSS, SIwave, Q3D, 2D Extractor Import data from a variety of sources Spice netlists, S-parameters, W-elements Analytical Models (RLC, Tline, diode ) IBIS Models Powerfull Post-processing including signal integrity metrics, such as SSN, SSO, TDR, BER and eye diagrams QuickEye TM and VerifEye TM Fast convolution and statistical eye analysis of transient solutions IBIS- AMI (Algorithmic Modeling Interface) 2010 ANSYS, Inc. All rights reserved. 16 ANSYS, Inc. Proprietary

Pre-Layout Channel 2D Model HFSS 2D Model HFSS 2D Model HFSS HFSS HFSS HFSS HFSS HFSS Port3 Port1 0 1 2 3 4 5 6 7 0 0

5 1 2 sw_p HFSS conn_p sw_n conn_n Switch ref HFSS + + - - conn_n mid_n VHDM Mid-Plane ref conn_p HFSS mid_p 0 W1239 0

conn_p HFSS blade_p conn_n Blade blade_n ref 1 2 blade_p HFSS smp_p blade_n Blade smp_n ref ref blade blade ref 0

(W-Elements from Q3D/2D) 3 = Connector Model (HFSS) 4 = Mid-plane PCB Model (W-Elements from Q3D/2D) 5 = Connector

17 Pre-Layout Channel 2D Model HFSS 2D Model HFSS 2D Model HFSS HFSS HFSS HFSS HFSS HFSS Port3 Port ref smp_p switch HFSS sw_p switch smp_n sw_n Switch ref ref sw_p HFSS conn_p sw_n conn_n Switch ref HFSS conn_n mid_n VHDM Mid-Plane ref conn_p HFSS mid_p 0 W W W mid_p mid_n HFSS ref ref conn_p HFSS conn_n Mid-Plane VHDM ref conn_p HFSS blade_p conn_n Blade blade_n ref 1 2 blade_p HFSS smp_p blade_n Blade smp_n ref ref blade blade ref 0 Port4 Port2 HFSS 0 = SMP Connectors (HFSS) 1 = Driver-Side Via Stub (Full Stackup HFSS Model) 2 = Switch PCB Model (W-Elements from Q3D/2D) 3 = Connector Model (HFSS) 4 = Mid-plane PCB Model (W-Elements from Q3D/2D) 5 = Connector Model (HFSS) 6 = Blade PCB Model (W-Elements from Q3D/2D) 7 = Receiver-Side Via Stub (Full Stackup HFSS Model) HFSS 2010 ANSYS, Inc. All rights reserved. 17 ANSYS, Inc. Proprietary

Post Layout Simulation 0 1HFSS 2 3 4 HFSS 5 0 SIwave SIwave SIwave 0 0 ref ref Port3 Port1 switch switch

sw- blade- ref blade blade Port4 Port2 ref 0 0 0 0 0 ref 0 0 HFSS 1 = Switch PCB Model (SIwave) 2 = Connector

18 Post Layout Simulation 0 1HFSS HFSS 5 0 SIwave SIwave SIwave 0 0 ref ref Port3 Port1 switch switch conn+ smp+ conn- smp- ref SWITCH smp+ conn+ smp- conn- ref HFSS C ref HFSS C ref Blade Mid-Plane sw+ blade+ sw- blade- ref blade blade Port4 Port2 ref ref 0 0 HFSS 1 = Switch PCB Model (SIwave) 2 = Connector Model (HFSS) 3 = Mid-plane PCB Model (SIwave) HFSS 2010 ANSYS, Inc. All rights reserved. 18 ANSYS, Inc. Proprietary

3 Steps to Analysis HSSD Performance 2010 ANSYS,

Component Analytical Model Transmissiom Line

link HFSS, Siwave, 2D Exttractor, Q3D Nport Model S

Spice, Spectre, HSPICE 1 2 P=1mm W1=1mm S1=1mm W2=1mm

21 Component Analytical Model Transmissiom Line Single/Differantial W-elements Imported Model Dynamic link HFSS, Siwave, 2D Exttractor, Q3D Nport Model S parameter, NMF C Model Matlab Model Imported Netlist Spice, Spectre, HSPICE 1 2 P=1mm W1=1mm S1=1mm W2=1mm sub=substrate W ANSYS, Inc. All rights reserved. 21 ANSYS, Inc. Proprietary

R10 50 ID=9 Simple Channel Example HFSS Model W

p3_n p4_p p1_n p2_p 2 2 0 0 0 0 S parameter 2010

Step 2: Check Frequency Domain Performance 2010

Y1 Y1 Frequency Domain: S, Y, Z parameter Ansoft LLC 0.00 Diferential S_Parameter ANSOFT Differential Terminal -10.00-20.00-30.00-40.00-50.

00 Terminal S_Parameter Curve Info ANSOFT db(s(port1,port1)) db(s(port1,port2)) -15.00-25.00-35.

24 Y1 Y1 Frequency Domain: S, Y, Z parameter Ansoft LLC 0.00 Diferential S_Parameter ANSOFT Differential Terminal Curve Info db(s(diff1,diff1)) db(s(diff1,diff2)) db(s(diff1,comm1)) F [GHz] Ansoft LLC Terminal S_Parameter Curve Info ANSOFT db(s(port1,port1)) db(s(port1,port2)) Port1 Port3 1 2 p1_n p2_p p3_n p4_p 1 2 p3_n p4_p p1_n 0.00 Port F [GHz] p2_p Port ANSYS, Inc. All rights reserved. 24 ANSYS, Inc. Proprietary

post-processing options Renormalize Re-order De-embed (if Gamma defined).

25 Designer - S-parameter Analyzer Matrix color-coded visualization Large data set handling Multiple formats and data types S, Y, Z matrices db, mag, phase Statistical values Average, min, max, std deviation Port post-processing options Renormalize Re-order De-embed (if Gamma defined). Passivity check option Multiple S-parameters support Statistical information 2010 ANSYS, Inc. All rights reserved. 25 ANSYS, Inc. Proprietary

00 XY Plot 1 S_Parameter Curve Info S11 db S parameters FreqDomain S12 db S parameters FreqDomain S11 db State Space StateSpace S12 db

26 Y1 Check State-Space Verify State-Space Macro Model over S parameter Option to create state-space in Frequency domain analysis Manage fitting accuracy Compare using plot or Network Analyzer Causality Check Ansoft LLC XY Plot 1 S_Parameter Curve Info S11 db S parameters FreqDomain S12 db S parameters FreqDomain S11 db State Space StateSpace S12 db State Space StateSpace ANSOFT F [GHz] 2010 ANSYS, Inc. All rights reserved. 26 ANSYS, Inc. Proprietary

Step 3: Check Time Domain Performance 2010 ANSYS,

values Overshoot, rise time High-Speed System Design and Analysis System performance metrics including Eye statistics Inter-symbol interference (ISI) Bit-error rate (BER) Data recovery Entire

28 Y1 [V] AEYEPROBE(out) Time Domain Study Ansoft Corporation 1.00E+000 VerifEye_Bathtub_jjb PostLayoutStat Signal Integrity and Timing Studies Standard transient waveform and serial data/clock analysis Investigate basic time-domain metrics Voltage max and min values Overshoot, rise time High-Speed System Design and Analysis System performance metrics including Eye statistics Inter-symbol interference (ISI) Bit-error rate (BER) Data recovery Entire high-speed interconnect 1.00E-001 Curve Info 1.00E-002 AEYEPROBE(out) VerifEyeAnalysis 1.00E E E E E E E E E E UnitInterval MX1: MX2: Ansoft LLC Delay Differential ANSOFT V(Out_Line_P)-V(Out_Line_N) spacing='0.6mm' Time [ns] 2010 ANSYS, Inc. All rights reserved. 28 ANSYS, Inc. Proprietary 0.00 Curve Info V(In_Line_P)-V(In_Line_N) spacing='0.6mm'

29 Which Analysis? Transient When non LTI Circuit VerifEye Statistical BER investigation QuickEye Fast Convolution IBIS AMI Fast Convolution with compiled model 2010 ANSYS, Inc. All rights reserved. 29 ANSYS, Inc. Proprietary

Designer - Transient Analysis Full SPICE accuracy variable timestep transient Full support for active and passive circuitry Solutions for frequency domain models State-space Convolution Passivity and

30 Designer - Transient Analysis Full SPICE accuracy variable timestep transient Full support for active and passive circuitry Solutions for frequency domain models State-space Convolution Passivity and Causality checking/enforcement Multiple numeric algorithms Trapezoidal Gear NDF2 Multiple DC convergence options Beta/device continuation Device continuation Pseudo-transient Modified beta/device Alpha, beta, & device 44 port S-parameter model 148,000 MOSFETs 1.7 Million Capacitors 500,000 Resistors 2010 ANSYS, Inc. All rights reserved. 30 ANSYS, Inc. Proprietary

AEYEPROBE(required) Designer - VerifEye Analysis Statistical based analysis Setup includes Risetime, jitter, equalization and bitrate Support for multiple probes at different locations in channel

31 AEYEPROBE(required) Designer - VerifEye Analysis Statistical based analysis Setup includes Risetime, jitter, equalization and bitrate Support for multiple probes at different locations in channel 8b/10b Encoding Parametric variation solutions VerifEye outputs Bit error rate (BER) contour and bathtub plots Post Analysis Jitter and Noise Gaussian and Uniform Ansoft Corporation 1.00E E E E E E E E E E E E E-011 XY Plot 1 Curve Info AEYEPROBE(required) VE_jitter_sweep Amplitude=' ' jitter='2ps' AEYEPROBE(required) VE_jitter_sweep Amplitude=' ' jitter='4ps' AEYEPROBE(required) VE_jitter_sweep Amplitude=' ' jitter='6ps' AEYEPROBE(required) VE_jitter_sweep Amplitude=' ' jitter='8ps' Statistical 1.00E UnitInterval 2010 ANSYS, Inc. All rights reserved. 31 ANSYS, Inc. Proprietary

Designer - QuickEye Analysis Convolution based bit analysis Setup includes Risetime, jitter, equalization custom bitrates and patterns Support for multiple probes at different locations in channel

32 Designer - QuickEye Analysis Convolution based bit analysis Setup includes Risetime, jitter, equalization custom bitrates and patterns Support for multiple probes at different locations in channel Parameters can be swept Peak Distortion Analysis 8b/10b Encoding QuickEye outputs Pulse response, contour plots, VT curves and eye diagrams Eye diagrams include Histograms, eye masks, mask violations, characteristics 2010 ANSYS, Inc. All rights reserved. 32 ANSYS, Inc. Proprietary

33 Designer-IBIS AMI IBIS AMI (IBIS Algorithmic Modeling Interface) New standard provides encryption alternative Analysis support, similar to QuickEye Impulse Response based Parameterized Model support Compiled Drivers and Receiver Models 2010 ANSYS, Inc. All rights reserved. 33 ANSYS, Inc. Proprietary

Determine worst case bit pattern - QE Peak

sources PRBS11 Peak Distortion Analysis 2010

35 Determine worst case bit pattern - QE Peak Distortion Analysis (PDA) Based on deviations in the step response Results can be used to provide the bit pattern for QuickEye eye sources PRBS11 Peak Distortion Analysis 2010 ANSYS, Inc. All rights reserved. 35 ANSYS, Inc. Proprietary

Evaluate Impact of TX Jitter - QE TX Jitter Jitter amplification is present TX DCD TX

37 Evaluate Impact of RX Jitter & Noise - QE Receiver Jitter/Noise Modeled with PDF distribution RX Gaussian RJ RX UJ RX Noise Gaussian Uniform Two options: Receiver jitter for time deviations in the clock Receiver noise for voltage deviations (e.g. power supply noise) 2010 ANSYS, Inc. All rights reserved. 37 ANSYS, Inc. Proprietary

Y1 Threshold Detection - VE Minimum Latch Overdrive Separate high/low decisions for BER Ansoft Corporation 1.00E+000 1.00E-001 1.00E-002 1.00E-003 1.00E-004 1.00E-005 1.00E-006 1.00E-007 1.00E-008 1.

38 Y1 Threshold Detection - VE Minimum Latch Overdrive Separate high/low decisions for BER Ansoft Corporation 1.00E E E E E E E E E E E E-011 XY Plot 2 channel_statistical 1.00E-012 AEYEPROBE(probe_out) 1.00E-013 VerifEye Amplitude=' V 1.00E-014 AEYEPROBE(probe_out)1 1.00E-015 Imported Amplitude=' V UnitInterval 2010 ANSYS, Inc. All rights reserved. 38 ANSYS, Inc. Proprietary Curve Info

of initial transient step response to ensure settling has occured Allows mixing of different bus

39 Crosstalk Analysis - QE and VE Cross-talk Analyses Independent voltages, resistances, FFE, DFE, data rates, phase relationships, bit patterns, and mixing of SE and Differential channels User has control of initial transient step response to ensure settling has occured Allows mixing of different bus architectures PCIe, SATA, SAS, DDR, ClKs, 2010 ANSYS, Inc. All rights reserved. 39 ANSYS, Inc. Proprietary

Feedback Equalizer N taps Automatic tap weight determination User specified (completely

40 Insert Equalization - QE Feed Forward Equalizer N taps (pre and post-cursor) Automatic tap weight determination User specified (completely parameterizable) tap weights Decision Feedback Equalizer N taps Automatic tap weight determination User specified (completely parameterizable) tap weights 2010 ANSYS, Inc. All rights reserved. 40 ANSYS, Inc. Proprietary

43 Validation:HDMI Channel This case highlights the benefits of the modular platform. TMDS (transition minimized differential signaling) is the serial-link spec used to transmit the data SPEEDS. A HDMI Type-A Test Adapter (provided by Efficere*) is used to interface HDMI assemblies to measurement equipment. *Efficere Technologies ANSYS, Inc. All rights reserved. 43 ANSYS, Inc. Proprietary

2.5m and 10m test adapter 2010 ANSYS, Inc.

45 HDMI Adapter Details cable to Sampling Scope and TDR head Blue cable PCB Traces SMA GPPO connector HDMI Receptacle HDMI Connector and Cable 2010 ANSYS, Inc. All rights reserved. 45 ANSYS, Inc. Proprietary

PCB microstrip Transmission line (W-element) models were output from the HFSS waveport

46 HDMI Adapter Design - HFSS HFSS used to design and model the GPPO connector launch virtual prototyping leads to industry-leading performance for adapter. PCB microstrip Transmission line (W-element) models were output from the HFSS waveport data. coax So three models with one simulation! 2010 ANSYS, Inc. All rights reserved. 46 ANSYS, Inc. Proprietary

47 TDR Measurement Detail: Adapter These other traces were created by disconnecting the adapter at different locations. They are helpful in constructing models and identifying exact locations SMA blue coax GPPO PCB mstrip DC1 receptacle HDMI cable HDMI connector 2010 ANSYS, Inc. All rights reserved. 47 ANSYS, Inc. Proprietary

HDMI Channel Validation SMA GPPO Measured Simulated blue cable pcb mstrip

Using IBIS-AMI Models to Maximize Performance Given SerDes EQ and Channel ISI & Loss

European IBIS Summit May 11, 2016 Turin, Italy Using IBIS-AMI Models to Maximize Performance Given SerDes EQ and Channel ISI & Loss Donald Telian, SiGuys Signal Integrity Consultant 2016 SiGuys SI Consulting