ICS94209

Third party brands and names are the property of their respective owners.

Integrated

Circuit

Systems, Inc.

94209 RevA - 04/27/01

Programmable Frequency Generator & Integrated Buffers for Pentium III Processor

Block Diagram

Recommended Application:

Single chip clock solution 630S chipset.

Output Features:

•

3 - CPU @ 2.5V

•

13 - SDRAM @ 3.3V

•

6- PCI @3.3V,

•

2 - AGP @ 3.3V

•

1- 48MHz, @3.3V fixed.

•

1- 24/48MHz, @3.3V selectable by I

(Default is 24MHz)

•

2- REF @3.3V, 14.318MHz.

Features:

•

Programmable ouput frequency.

•

Programmable ouput rise/fall time.

•

Programmable SDRAM and CPU skew.

•

Spread spectrum for EMI control typically

by 7dB to 8dB,

with programmable spread percentage.

•

Watchdog timer technology to reset system

if over-clocking causes malfunction.

•

Uses external 14.318MHz crystal.

•

FS pins for frequency select

Skew Specifications:

•

CPU - CPU: < 175ps

•

SDRAM - SDRAM < 250ps (except SDRAM12)

•

PCI - PCI: < 500ps

•

CPU (early) - PCI: 1-4ns (typ. 2ns)

Functionality

Pin Configuration

48-Pin 300mil SSOP

* These inputs have a 120K pull down to GND.

PLL2

PLL1

Spread

Spectrum

48MHz

24_48MHz

CPUCLK (2:0)

SDRAM (12:0)

PCICLK (4:0)

AGP (1:0)

PCICLK_F

2

5

13

3

2

X1

X2

XTAL

OSC

CPU

DIVDER

SDRAM

DIVDER

PCI

DIVDER

Stop

Stop

Stop

SDATA

SCLK

FS(3:0)

PD#

PCI_STOP#

CPU_STOP#

SDRAM_STOP#

MODE

AGP_SEL

Control

Logic

Config.

Reg.

/ 2

REF(1:0)

AGP

DIVDER

VDDA

(AGPSEL)REF0

*(FS3)REF1

GND

X1

X2

VDDPCI

*(FS1)PCICLK_F

*(FS2)PCICLK0

PCICLK1

PCICLK2

PCICLK3

PCICLK4

GND

VDDAGP

AGPCLK0

AGPCLK1

GND

GND

*(FS0)48MHz

*(MODE)24_48MHz

VDD48

SDATA

SCLK

1

1

*

VDDL

CPUCLK0

CPUCLK1

CPUCLK2

GND

VDDSDR

SDRAM0

SDRAM1

SDRAM2

GND

SDRAM3

SDRAM4

SDRAM5

VDDSDR

SDRAM6

SDRAM7

GND

SDRAM8/PD#

SDRAM9/SDRAM_STOP#

GND

SDRAM10/PCI_STOP#

SDRAM11/CPU_STOP#

SDRAM12

VDDSDR

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

48

47

46

45

44

43

42

41

40

39

38

37

36

35

34

33

32

31

30

29

28

27

26

25

0

0

0

0

66.67

66.67

33.33

66.67

50.00

0

0

0

1

100.00

100.00

33.33

66.67

50.00

0

0

1

0

166.67

166.67

33.33

66.66

55.56

0

0

1

1

133.33

133.33

33.33

66.67

50.00

0

1

0

0

66.67

100.00

33.33

66.67

50.00

0

1

0

1

100.00

66.67

33.33

66.67

50.00

0

1

1

0

100.00

133.33

33.33

66.67

50.00

0

1

1

1

133.33

100.00

33.33

66.67

50.00

1

0

0

0

112.00

112.00

33.60

67.20

56.00

1

0

0

1

124.00

124.00

31.00

62.00

46.50

1

0

1

0

138.00

138.00

34.50

69.00

51.75

1

0

1

1

150.00

150.00

30.00

60.00

50.00

1

1

0

0

66.67

133.33

33.33

66.67

50.00

1

1

0

1

100.00

150.00

30.00

60.00

50.00

1

1

1

0

150.00

100.00

30.00

60.00

50.00

1

1

1

1

160.00

120.00

30.00

60.00

48.00

AGP

SEL = 0

AGP

SEL = 1

CPU

SDRAM PCICLK

FS3FS2 FS1FS0

ICS reserves the right to make changes in the device data identified in

this publication without further notice. ICS advises its customers to

obtain the latest version of all device data to verify that any

information being relied upon by the customer is current and accurate.