Intel 440GX manual 3.18.3 82558B LOM Checklist, Design Checklist

Models: 440GX

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3.18.382558B LOM Checklist

Design Checklist

Analog inputs feed inverting op-amp stages, useful for monitoring power supply regulation.

The LM79 is a 5V part, however SMBus requires a 3.3V interface. Level translation circuitry is required. See the reference schematics for an example circuit.

CHASSIS_INTRU and FAN3 are pulled down and SMI_IN# is pulled up with 10K ohm resistors.

The LM79 is connected to a programmable chip select on the PIIX4E. This assumes that the LM79 is tied to the X-Bus. See PIIX4 Datasheet for more details.

3.18.382558B LOM Checklist

Refer to Application Note # 383, Intel 82558 LAN on Motherboard Design Guide, for recommended PHY conformance testing (i.e., IEEE testing) and additional LOM design details.

The PWR_GOOD circuitry (shown in Ap-Note 383) should be implemented if the power supply dose not provide this signal.

Additional logic is needed to ensure that at least 4 clock cycles occur between ALTRST# and ISOLATE# assertion.

The distance between “Magnetics” (i.e., Cat-3 or Cat-5 wire) and RJ-45 connector should be kept to less than one inch.

Symmetrical 100 ohm traces should be used (differential impedance) for TDP/TDN and RDP/ RDN.

The 82558 requires decoupling on the power pins. At minimum, 3 capacitors (2 x 0.1uF and 1 x 4.7uF) should be implemented on each side.

High speed traces between the 82558 to magnetic or magnetic to RJ45 should be routed between layers to protect from EMI.

Pull-up resistors and values are recommended for the following pins:

Pin Number

Pin Name

Resistor Value

Comment

 

 

 

 

15

ZREF

10K (5%)

Required in both A and B stepping designs

 

 

 

 

Pull-down resistors and values are recommended for the following pins:

Pin Number

Pin Name

Resistor Value

Comment

 

 

 

 

30

TEST

1K (5%)

 

 

 

 

 

153

FLD4

10K (5%)

Not required for B-stepping designs

 

 

 

 

154

FLD3

10K (5%)

Not required for B-stepping designs

 

 

 

 

171

RDP

49.9 (1%)

 

 

 

 

 

172

RDN

49.9 (1%)

 

 

 

 

 

180

VREF

220 (5%)

 

181

RBIAS10

768 (1%)

 

 

 

 

 

182

RBIAS100

634 (1%)

 

 

 

 

 

187

TDN

49.9 (1%)

 

 

 

 

 

204

AUXPWR#

220 (5%)

 

 

 

 

 

Intel®440GX AGPset Design Guide

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Page 94
Image 94
Intel 440GX manual 3.18.3 82558B LOM Checklist, Design Checklist