The Accelerated Graphics Port (AGP) interface is a platform bus specification that enables high-performance graphics capabilities, 3-D, and video--over networks as well as on individual PCs. Platform-independent, AGP is supported by numerous hardware and software vendors, and is now a standard on Intel-based platforms. Software and hardware engineers working with graphics must have a good understanding of this important technology.
AGP System Architecture, Second Edition includes all the essentials from the first edition, but has been expanded and reorganized for even better coverage. This comprehensive and concise book provides an overview of the technology, a detailed description of the specification, a discussion of AGP Pro, and a practical tutorial for mastering AGP. In particular, it focuses on 3-D graphics and video-related applications most served by AGP. It also provides a primer for the PCI bus protocol as background for a discussion on AGP and analyzes the advantages of AGP over PCI for 3-D graphics. You will find coverage of the following essential topics:
This indispensable resource will enable you to understand AGP tools, design a high-quality AGP device, and support AGP in software applications.
The PC System Architecture Series is a crisply written and comprehensive set of guides to the most important PC hardware standards. Each title is designed to illustrate the relationship between the software and hardware, and thoroughly explains the architecture, features, and operation of systems built using the targeted technology.
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1. The 3D Graphics Challenge.
3D Graphics Compute- and Memory-Intensive.
Local Versus Main Memory.
PCI Graphics Adapter.
Intro To AGP Graphics Adapter.
Example Enumeration/Configuration of AGP.
Host/PCI Bridge PCI Bus 0, Device 0, Function 0.
AGP Enable/Disable Bit.
Discovering Host/PCI Bridge's AGP Register Set.
NB Connects To AGP Bus via PCI-to-PCI Bridge.
PCI-to-PCI Bridge's Configuration Registers.
Assigning AGP Bus Number.
Device At Other End of Bus Needn't Be a Graphics Adapter.
Discovering AGP Graphics Adapter.
Discovering Adapter's AGP Capability Register Set.
Setting Up Adapter's BAR Registers.
Introduction To Dynamic Memory Allocation.
AGP Aperture Implementation.
Intro to Windows Software Environment.
BIOS Initialization Requirements.
Operating System Initialization Requirements.
Some Basic Rules For Both Reads and Writes.
Example Single Data Phase Read.
Example Burst Read.
Treatment of Byte Enables During Read or Write.
Performance During Read Transactions.
Example Single Data Phase Write Transaction.
Example Burst Write Transaction.
Performance During Write Transactions.
PCI Is Not An Efficient Bus.
Decoupling Address and Data Phases Optimizes Bus Usage.
Issuing Transaction Requests.
PCI Bus Master Can Write to AGP Adapter's Local Memory.
GART Support for PCI Masters Is Optional.
Monochrome Device Adapter (MDA) Support.
Required Versus Optional Features.
PCI Target Latency Rules Don't Apply to North Bridge.
AGP Graphics Adapter Cannot Use Subtractive Decode.
North Bridge/AGP Adapter Interconnect Examples.
Introduction To Signal Description.
AGP Clock Signal.
The Signaling Environment (I/O Voltage).
Where Is the AGP Bus Arbiter Located?
Signal Usage In AGP Transactions.
Signal Usage In PCI Transactions.
Signal Usage in Fast Write Transactions.
Special Overflow Prevention Signals.
Unimplemented PCI Signals.
Pull-Up and Pull-Down Resistor Values.
Number of Devices.
Signal Routing and Layout.
Trace Impedance and Line Termination.
Add-in Card Clock Skew Specifications.
AGP Voltage Characteristics.
Component Pinout Recommendations.
Motherboard/Add-in Card Interoperability.
Maximum AC Ratings and Device Protection.
Power Supply. Mechanicals.
1x Transfer Mode Timing Parameters.
2x and 4x Transfer Mode Timing Model.
Changes to Clock Frequencies in Mobile Designs.
Command Types and the Transfer Length.
AGP Ordering Rules.
The AGP Arbiter.
Maximizing Bus Usage via GNT# Pipelining.
Two Request Generation Mechanisms.
AGP Request Queue Depth.
Issuing Transaction Requests via AD and C/BE buses.
Issuing Transaction Requests via the SBA Port.
In AGP, Data Is Transferred in Blocks.
Wait State Before First Data Block.
Inserting Wait States Between Blocks.
Data Transfer Size Can Be Less Than a Data Block.
Usage of Byte Enables.
But Minimum Data Transaction Is One Clock Long.
Three Times Where Data Transfer Can Be Delayed.
AGP Adapter's Control of Data Transfers.
North Bridge's Control of Data Transfers.
RBF# Prevents Return of Low-Priority Read Data.
Multiple Data Block Read Transaction.
Multiple Block Read Data Transfer with Wait States.
Read Data Transaction, Wait State Before First Block.
Write Data Transaction, No Initial Wait State.
Back-to-Back Write Data Transactions, No Delays.
2x Transfer Mode Data Transactions.
Back-to-Back Read Transfers, No Wait States.
Multiple Block Read, No Wait States.
Multiple Block Write with Wait States.
Back-to-Back Write Data Transactions, Minimum Delay.
Using Strobe Falling-Edges To Latch Data.
Using Strobe Crossover Point to Latch Data.
Back-to-Back Read Data Transactions, No Wait States.
Multiple Block Read, No Wait States.
Multi-Block Read with Wait State Before 2nd Data Block.
Back-to-Back Write Data Transactions, No Wait States.
Use of WBF# to Prevent Start of Fast Write.
Arbitration to Perform a Fast Write.
Introduction to the Fast Write Transaction.
Fast Write Transactions in 2x Mode.
Fast Write Transactions in 4x Mode.
Adapter-Initiated Premature Transaction Termination.
Master-Initiated Premature Transaction Termination.
Back-to-Back Fast Write Transactions.
Two Fast Write Transactions with No Idle in Between.
Use of the WBF# Signal.
Short, Fast Write Transactions and DEVSEL#.
Many Transaction Pairs Require Turnaround Cycle(s).
AGP Write Data Followed by Fast Write.
AGP Write Data Followed by AGP Read Data.
AGP Pro Connector.
Requires Two Adjacent PCI Connectors.
High-Power AGP Pro Card.
Low-Power AGP Pro Card.
Card Power Indication.