Integrated

Circuit

Systems, Inc.

AMD - K7™ System Clock Chip

Recommended Application:

VIA K7 style chipset

Output Features:

1 - Differential pair open drain CPU clocks

1 - Single-ended open drain CPU clock

13 - SDRAM @ 3.3V

6 - PCI @3.3V,

1 - 48MHz, @3.3V fixed.

1 - 24148MHz @ 3.3V

2 - REF @3.3V, 14.318MHz.

Features:

Up to 155MHz frequency support

Support pow�r management: CPU stop and Power down

Mode from I C programming.

Spread spectrum for EMI control (0 to -0.5% down

spread, ± 0.25% center spread).

Uses external 14.318MHz crystal

Skew Specifications:

CPUT - CPUC: <200ps

PCI - PCI: <500ps

CPU - PCI: <1-3ns

VDD1

REF0/CPU_STOP#*

GND

X1

X2

VDD2

*MODE/PCICLK_F

*FS3/PCICLK0

GND

*SEL24_48#/PCICLK1

PCICLK2

PCICLK3

PCICLK4

VDD2

BUFFER IN

GND

SDRAM11

SDRAM10

VDD3

SDRAMg

SDRAM8

GND

SDATA

SCLK

ICS9248-114

Pin Configuration

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

48-Pin 300mil SSOP

REF1/FS2*

GND

CPUCLKT1

GND

CPUCLKC0

CPUCLKT0

VDDL

PD#*

SDRAM OUT

GND

SDRAM0

SDRAM1

VDD3

SDRAM2

SDRAM3

GND

SDRAM4

SDRAM5

VDD3

SDRAM6

SDRAM7

VDD4

48MHz/FS0*

24/48MHz/FS1*

* Internal Pull-up Resistor of 120K to VDD

Block Diagram

Functionality

X1

X2

SEL24_48#

SDATA

SCLK

FS(3:0)

PD#

CPU_STOP#

BUFFER IN

I

,----,

I

I

PLL2 t-----,---t------t

48MHz

Control

Logic

Config.

Reg.

-----------------'

24_48MHz

REF(1:0)

CPUCLKC0

CPUCLKT(1:0)

PCICLK(4:0)

PCICLK_F

SDRAM(11:0)

SDRAM_OUT

FS3

FS2

0

0

0

0

0

0

0

0

0

1

0

1

0

1

0

1

1

0

1

0

1

0

1

0

1

1

1

1

1

1

1

1

FSl

FS0

CPU

PCICLK

(MHz)

(MHz)

0

0

124.00

41.33

0

1

75.00

37.50

1

0

83.30

41.65

1

1

66.80

33.40

0

0

103.00

34.33

0

1

112.00

37.33

1

0

133.30

44.43

1

1

100.00

33.33

0

0

120.00

40.00

0

1

115.00

38.33

1

0

110.00

36.67

1

1

105.00

35.00

0

0

140.00

35.00

0

1

150.00

37.50

1

0

124.00

31.00

1

1

133.30

33.33

'1�9� 2�48� 1�1•4-•R_•_•_D�1•2_/•2_8•/_0•1�1---------------------!'!!'!IC!'!!'!S!'!!'!r!'!!'! e !'!!'!se!'!!'!rv!'!!'!e !'!!'!s t!'!!'!h!'!!'!er!'!!'!ig!'!!'!h!'!!'!t !'!!'!to!'!!'!m!'!!'!a!'!!'!ke!'!!'!c!'!!'!h!'!!'!an!'!!'!g !'!!'!es!'!!'!in!'!!'!!'th!'!!'!e !'!!'!de!'!!'!v!'!!'!ic!'!!'!e !'!!'!da!'!!'!ta!'!!'!i!'!!'!de!'!!'!n!'!!'!ti!'!!'!fi e!'!!'! d!'!!'!in!!!'!!'!

,

•

ev

thispublication wi thou t fur th er no tic e. JCS advisesitscustom ers to

Thirdpartybrandsandnamesare the property oftheir respective owners.

obtain th e lat est version ofall devic e data to verify that an y

information being relie d upon by th e custom er iscurr en t an d accurat e.