IDT 89HPES24N3A, User Manual

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Notes
PES24N3A User Manual i April 10, 2008
Table of Contents
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About This Manual
Introduction ....................................................................................................................................1
Content Summary .......................................................................................................................... 1
Signal Nomenclature ..................................................................................................................... 1
Numeric Representations ..............................................................................................................2
Data Units ......................................................................................................................................2
Register Terminology ..................................................................................................................... 3
Use of Hypertext ............................................................................................................................ 4
Reference Documents ................................................................................................................... 4
Revision History ............................................................................................................................. 4
PES24N3A Device Overview
Introduction .....................................................................................................................................1-1
List of Features ...............................................................................................................................1-1
System Diagrams............................................................................................................................1-3
Logic Diagram.................................................................................................................................1-4
System Identification.......................................................................................................................1-5
Vendor ID................................................................................................................................1-5
Device ID ................................................................................................................................1-5
Revision ID .............................................................................................................................1-5
JTAG ID..................................................................................................................................1-5
SSID/SSVID............................................................................................................................1-5
Device Serial Number Enhanced Capability...........................................................................1-5
Pin Description................................................................................................................................1-6
Pin Characteristics..........................................................................................................................1-9
Clocking, Reset, and Initialization
Introduction .....................................................................................................................................2-1
Initialization .....................................................................................................................................2-3
Reset...............................................................................................................................................2-4
Fundamental Reset ................................................................................................................2-4
Hot Reset................................................................................................................................2-6
Upstream Secondary Bus Reset ............................................................................................2-7
Downstream Secondary Bus Reset........................................................................................2-7
Downstream Port Reset Outputs ....................................................................................................2-8
Power Enable Controlled Reset Output..................................................................................2-8
Power Good Controlled Reset Output ....................................................................................2-9
Hot Reset Controlled Reset Output ........................................................................................2-9
Theory of Operation
Introduction .....................................................................................................................................3-1
Data Paths ......................................................................................................................................3-2
Store-and-Forward vs. Cut-Through Switching and Latency..........................................................3-2
Switch Core.....................................................................................................................................3-3
Transaction Routing................................................................................................................3-4
Transaction Reordering ..........................................................................................................3-4
Scheduling and Port Arbitration..............................................................................................3-5