Intel740™ Graphics Accelerator Design Guide
3-3
3 Device AGP MotherBoard Design
3.1.4
Implementation Issues
The following are design issues involved in implementing a 3-load AGP bus. These issues must be
studied and implemented carefully in order to produce a functional design.
3.1.4.1
Disabling A Master Device
There are two master devices that must each have the ability to be disabled in a logical point-to-
point bus. These devices are the master graphics controller on the motherboard and the master
graphics controller on the AGP add-in card. Several issues effect the ability to, and the way in
which, a master graphics controller is disabled.
One issue concerns the add-in card and the other concerns the graphics controller components
themselves. Since the current AGP specification has made no provision for a general method of
disabling a master device, this function must be defined for on an individual basis depending on the
operating characteristics of each master device. The graphics controller that is used as the down
device on the motherboard must have a mechanism that disables the device in a manner acceptable
to the implementation of a logical point-to-point bus. The Intel 740 has such a mechanism that
Figure 3-1. Pentium
®
II
Processor / Intel
®
440BX AGPset/Intel 740 Graphics Accelerator
System Block Diagram
sys_blk.vsd
Host Bus
82443BX
Host Bridge
Main
Memory
Pentium
®
II
Processor
SDRAM Support
72 Bit
w/ECO
AGP Bus
Intel 740
Grahics
Accelerator
Display
ISA Bus
ISA Slots
System BIOS
System Mgnt (SM) Bus
2 IDE Ports
(Ultra DMA/33)
2 USB
Ports
USB
USB
IO
APIC
82371EB
(PIIX4E)
(PCI-to-ISA
Bridge)
Primary PCI Bus
(PCI Bus #0)
PCI Slots
Graphics
Local Memory
66/100
MHz
AGP SLOT
Summary of Contents for 740
Page 1: ...Intel740 Graphics Accelerator Design Guide August 1998 Order Number 290619 003 ...
Page 9: ...1 Introduction ...
Page 10: ......
Page 13: ...2 Intel740 Graphics Accelerator Addin Card Design ...
Page 14: ......
Page 40: ...Addin Card Design 2 26 Intel740 Graphics Accelerator Design Guide ...
Page 57: ...3 Intel740 Graphics Accelerator 3 Device AGP Motherboard Design ...
Page 58: ......
Page 86: ...3 Device AGP MotherBoard Design 3 28 Intel740 Graphics Accelerator Design Guide ...
Page 128: ...4 Thermal Considerations ...
Page 129: ......
Page 131: ...Thermal Considerations 4 2 Intel740 Graphics Accelerator Design Guide ...
Page 132: ...5 Mechanical Information ...
Page 133: ......
Page 139: ...Mechanical Information 5 6 Intel740 Graphics Accelerator Design Guide ...
Page 140: ...6 Third Party Vendors ...
Page 141: ......
Page 144: ...A Application Notes ...
Page 172: ...Intel740 Graphics Accelerator Thermal Design Considerations 24 Application Note 653 ...
Page 174: ......
Page 178: ......
Page 183: ......
Page 185: ...B Reference Information ...
Page 186: ......
Page 187: ...PC SGRAM Specification Revision 0 9 February 1998 Order Number Not Applicable ...