SM8702AM

NIPPON PRECISION CIRCUITS—1

NIPPON PRECISION CIRCUITS INC.

Clock Generator IC

OVERVIEW

The SM8702AM is a clock generator IC that can generate clock signals up to and exceeding 100MHz for per-

sonal computer (PC) motherboards. It uses a single 14.318MHz crystal oscillator element and 2 built-in PLLs

to simultaneously and independently generate 2 CPU clocks, 6 PCI bus clocks, 2 reference clocks with the

same frequency as the crystal element, 48MHz USB interface clock, and 24MHz Super I/O chip clock outputs.

It also has 14 outputs that can function as SDRAM clocks by buffering an external input SDRAM clock.

FEATURES

s

compatibles supported

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2.5/3.3V CPU clock outputs and IOAPIC clock

output

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14

× SDRAM clock outputs (3 DIMMs)

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2

× CPU clock outputs

(60), 66, 75, 83, 95, 100, 103, 112, (124), 133MHz

CPU/SDRAM clock frequencies. Values in paren-

theses are available as mask options.

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6

× PCI bus clock outputs (one free-running out-

put)

33MHz or 1/2, 1/3, 1/4 of the CPU clock fre-

quency

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2

× reference clock outputs and 1 × IOAPIC clock

output

14.318MHz REF/IOAPIC clock frequency

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1

× 48MHz USB interface clock output

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1

× 24MHz clock output for Super I/O chip

s

trol

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CPU-stop and PCI-stop functions

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Spread Spectrum Clock Generator (SSCG) out-

puts

Center spread/Down spread, ± 0.5% or ± 1.5%

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3.3V (VDD) and 2.5/3.3V (VDDL) supply volt-

ages

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48-pin SSOP package (pin compatible with

ICS9148-26)

APPLICATIONS

s

ture CPUs

PINOUT

48-pin SSOP (300 mil)

(Top view)

ORDERING INFORMATION

AMD and AMD-K6 are registered trademarks of Advanced Micro Devices, Inc..

D e vice

P a ck ag e

SM8702AM

48-pin SSOP

VDD1

REF0

VSS

XT

XTN

VDD2

PCICLK_F/MODE

VDDL1

IOAPIC

REF1/FS2

VSS

CPUCLK0

CPUCLK1

VDDL2

PCICLK0

SDRAM13

VSS

PCICLK1

SDRAM12

VSS

148

PCICLK2

PCICLK3

SDRAM0

SDRAM1

PCICLK4

VDD2

BUFFERIN

VSS

SDRAM11/CPU_STOP#

SDRAM10/PCI_STOP#

VDD3

SDRAM9

SDRAM8

VSS

SDATA

SCLK

VDD3

SDRAM2

SDRAM3

VSS

SDRAM4

SDRAM5

VDD3

SDRAM6

SDRAM7

VDD4

48MHz/FS0

24MHz/FS1

24

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