TDR/TDT Simulation Tutorial
Product Version Sigrity 2018
March 2019
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Contents
1
Introduction
Overview
Sample Case
2
Layout Setup
Loading Layout File
Checking Stackup
Choosing Nets
3
TDR/TDT Single Ended Simulation
Setting Up TDR/TDT Circuit Model
Generating TDR/TDT Ports Automatically
Generating TDR/TDT Ports Manually
Linking TDR/TDT Circuits to Board Manually
Choosing Ports for Simulation
Running Simulation
Viewing Result
4
TDR/TDT Differential Simulation
Enabling Differential Nets
Setting Up TDR/TDT Circuit Model
Generating TDR/TDT Ports Automatically
Generating TDR/TDT Ports Manually
Selecting Ports for Simulation
Running Simulation
Viewing Results
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TDR/TDT Simulation Tutorial
Table of Contents
1
Introduction
This tutorial demonstrates how to use TDR (Time-Domain Reflectometry)/TDT (Time-Domain
Transmission) mode in SPEED2000 to simulate the measurement of TDR/TDT for signal integrity
analysis.
The TDR/TDT mode in SPEED2000 enables user to easily check the signal's propagation,
reflection and impedance discontinuity by step pulse response. The simulation results can better
show voltage and impedance variation with time, helping user to check the quality of signal
propagation channel. And the impedance discontinuous position on board can be calculated by the
time and signal propagation velocity.
Overview
SPEED2000 provides the following functions in TDR/TDT mode:
Create TDR/TDT circuits automatically
Create TDR/TDT circuits manually
Calculate impedance at TDR/TDT circuits
Display TDR/TDT voltages
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TDR/TDT Simulation Tutorial
Introduction
The TDR/TDT workflow leads user to:
Setup layout
Setup TDR/TDT
Setup other simulation options
Run simulation
View simulation results
Sample Case
The original layout file used in this tutorial is:
SODIMM_TDR_TDT.spd
It is located in: <Sigrity_install_dir>\share\SpeedXP\Samples\SPEED2000\TDR-TDT
Simulation\Examples_PreSetup\
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TDR/TDT Simulation Tutorial
Introduction