AMD 8 manual the AMD Athlon Processor-Based Motherboard Design Guide, Preliminary Information

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the AMD Athlon™ Processor-Based Motherboard Design Guide,

Preliminary Information

AMD Athlon™ XP Processor Model 8 Data Sheet

25175H— March 2003

Table 28. VID[4:0] Code to Voltage Definition

VID[4:0]

VCC_CORE (V)

VID[4:0]

VCC_CORE (V)

00000

1.850

10000

1.450

 

 

 

 

00001

1.825

10001

1.425

 

 

 

 

00010

1.800

10010

1.400

 

 

 

 

00011

1.775

10011

1.375

 

 

 

 

00100

1.750

10100

1.350

 

 

 

 

00101

1.725

10101

1.325

 

 

 

 

00111

1.675

10111

1.275

 

 

 

 

01000

1.650

11000

1.250

 

 

 

 

01001

1.625

11001

1.225

 

 

 

 

01010

1.600

11010

1.200

 

 

 

 

01011

1.575

11011

1.175

 

 

 

 

01100

1.550

11100

1.150

 

 

 

 

01101

1.525

11101

1.125

 

 

 

 

01110

1.500

11110

1.100

 

 

 

 

01111

1.475

11111

No CPU

 

 

 

 

 

For more information, see the “Required Circuits” chapter of

 

the AMD Athlon™ Processor-Based Motherboard Design Guide,

 

order# 24363.

VREFSYS Pin

VREFSYS (W5) drives the threshold voltage for the system bus

 

input receivers. The value of VREFSYS is system specific. In

 

addition, to minimize VCC_CORE noise rejection from VREFSYS,

 

include decoupling capacitors. For more information, see the

 

AMD Athlon™ Processor-Based Motherboard Design Guide, order#

 

24363.

ZN and ZP Pins

ZN (AC5) and ZP (AE5) are the push-pull compensation circuit

 

pins. In Push-Pull mode (selected by the SIP parameter

 

SysPushPull asserted), ZN is tied to VCC_CORE with a resistor

 

that has a resistance matching the impedance Z0 of the

 

transmission line. ZP is tied to VSS with a resistor that has a

 

resistance matching the impedance Z0 of the transmission line.

80

Pin Descriptions

Chapter 11

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AMD 8 manual the AMD Athlon Processor-Based Motherboard Design Guide, Preliminary Information, Pin Descriptions