Chapter 9: Methodology Overview; Introduction - Xilinx Virtex-4 RocketIO User Manual

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Methodology Overview

Introduction

Xilinx, in partnership with Dr. Howard Johnson, has developed a two-part DVD tutorial
on signal integrity techniques and loss budgeting for RocketIO transceivers.
DVDs cover in more detail much of the material in
User Guide.
Figure 9-1
gigabit transceivers (MGTs). Any physical link connecting two point-to-point high-speed
serial transceivers is defined as a channel. A channel begins at the die solder bumps of the
transmitter and ends at the die solder bumps of the receiver.
TX
In
transitions.
Transitions are defined as any section along a multi-gigabit channel where the signal must
go from a transmission line to a three-dimensional structure or vice-versa. Vias,
connectors, and coupling capacitors are examples of these structures.
While a more comprehensive list of transitions is discussed in
Transitions,"
•
•
•
•
•
For optimal performance, the following must be minimized in a given channel:
•
Virtex-4 RocketIO MGT User Guide
UG076 (v4.1) November 2, 2008
shows a typical physical interconnect topology between two RocketIO multi-
BGA Break-Out
TXP
Daughter Card
TXN
Package Striplines or Microstrips
Figure 9-1: Two RocketIO MGTs Interconnected
Figure 9-1, the channel consists of the FPGA package, transmission lines, connectors and
some common transitions are:
Ball grid array (BGA) to PCB microstrip
Microstrip to stripline vias
DC blocking capacitors
Connectors
Bends and turns in a trace
Signal attenuation due to losses in the transmission medium
www.xilinx.com
Chapter 9 through
Connector
Transition
Backplane
Connector pins
Chapter 9
[Ref 2] These
Chapter 12 of this
Other half
mirrored to RX
ug072_c3_01_030106
Chapter 11, "Design of
235