Integrated

Circuit

Systems, Inc.

General Description

Features

ICS9341

Block Diagram

133MHz Clock Generator and Integrated Buffer for PowerPC™

9341 Rev A 10/12/99

Pin Configuration

48-pin SSOP

* Internal pull-up resistor of 120K to 3.3V on

indicated inputs

** Internal pull-down resistor of 120K to GND

on indicated inputs.

Generates the following system clocks:

- 4-CPUA(3.3V, up to 133MHz)

- 4-CPUB (3.3V, up to 133MHz)

- 8-PCI(3.3V,33.3MHz)

- 1-OUT(3.3v,64MHz)

- 1-OUT/2(3.3V,OUT/2MHz)

- 2-REF(3.3V,14.318MHz)

±.25% center spread

Skew characteristics:

- CPU - CPU: <350ps

- CPU - PCI: <500ps

- PCI - PCI: <500ps

The ICS9341 generates all clocks required for high speed

PowerPC RISC microprocessor systems. Generating clocks in

phase with an external reference frequency.

Spread Spectrum may be enabled by driving the SS_EN pin

active. Spread spectrum typically reduces system EMI by 8dB

to 10dB. This simplifies EMI qualification without resorting to

board design iterations or costly shielding. The ICS9341

employs a proprietary closed loop design, which tightly

controls the percentage of spreading over process and

temperature variations.

Power Groups:

VDDREF,GNDREF=REF,X1,X2

GNDPCI,VDDPCI=PCICLK

VDD66,GND66=3V66

VDD48,GND48=48MHz

VDDCOR,GNDCOR=PLLCore

VDDLCPU/2,GNDLCPU/2=CPU/2

VDDLIOAPIC,GNDIOAPIC=IOAPIC

PD#

CPUB_STOP#

OUT_SEL (0:1)

PCI_STOP#

SS_EN

X1

X2

OSC

PLL

Spread

Spectrum

REF (0:1)

2

4

4

OUT

OUT/2

CPUCLKB (1:4)

CPUCLKA (1:4)

STOP

C

o

n

t

r

o

l

/ 2

PLL2

8

PCICLK (1:8)

STOP

/ 8

/ 6

/ 5

/ 4

/ 2

/ 4

/ 5

/ 6

/ 3

GNDREF

X1

X2

VDDPCI

PCICLK1

PCICLK2

PCICLK3

PCICLK4

GNDPCI

GNDCPUB

CPUB1

CPUB2

CPUB3

CPUB4

VDDCPUB

VDDPCI

PCICLK5

PCICLK6

PCICLK7

PCICLK8

FS0

FS1

*OUT_SEL0

GNDPCI

REF1

REF0

VDDREF

CPUA1

CPUA2

SS_EN

GNDCPUA

OUT_SEL1*

PD#

VDDCPUA

CPUA3

CPUA4

CPUB_STOP#**

VDDD

VDDOUT

OUT

OUT/2

GNDOUT

GNDA

GNDD

N/C

N/C

*PCI_STOP#

VDDA

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

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.