Integrated

Circuit

Systems, Inc.

General Description

Features

ICS9169C-232

Block Diagram

Frequency Generator for Pentium™ Based Systems

9169C-232RevB031897

Pin Configuration

28-Pin SOIC or SSOP

Functionality

3.3V±10%, 0-70

Crystal (X1, X2) = 14.31818 MHz

Pentium is a trademark of Intel Corporation.

•

Strong output drive.

•

Eight selectable CPU clocks operate up to 83.3 MHz

•

Frequency selections include Turbo-mode speed of 68.5

MHz

•

Maximum CPU jitter of ±200ps

•

Six BUS clocks support sync or async bus operation

•

250ps skew window for CPU outputs, 500ps skew window for

BUS outputs

•

CPU clocks to BUS clocks skew 1-4 ns (CPU early)

•

48 MHz clock for USB support & 24 MHz clock for FD.

•

Logic inputs latched at Power-On for frequency selection

saving pins as Input/Output

•

Integrated buffer outputs drive up to 30pF loads

•

3.0V - 3.7V supply range, CPU (1:6) outputs 2.5V

(2.375 - 2.6V) VDD option

•

28-pin SOIC or SSOP package

The ICS9169C-232 is a low-cost frequency generator

designed specifically for Pentium and Pentium-Pro based

chip set systems. The integrated buffer minimizes skew

and provides all the clocks required. A 14.318 MHz XTAL

oscillator provides the reference clock to generate standard

Pentium frequencies. The CPU clock makes

gradual

frequency transitions without violating the PLL timing of

internal microprocessor clock

multipliers. A raised

frequency setting of 68.5 MHz is available for Turbo-mode

of the 66.8 MHz CPU. The ICS9169C-232 contains 8 CPU

clocks, 6 PCI clocks, 1 REF at 48MHz and 1 at 24MHz.

Either synchronous (CPU/2) or asynchronous (32 MHz)

PCI bus operation can be selected by latching data on

BSEL input.

ADD RESS

SEL ECT

CP U( 1:8)

(MHz)

BU S (1:6)MHz

48MHz 24MHz

RE F

FS2 FS1

FS0

BSEL=1 BSEL=0

0

0

0502532

48

24

REF

0

0

1603032

48

24

REF

0

1

0

66.8

33.4

32

48

24

REF

01

1

75.9

32

32

48

24

REF

10

0

55

27.5

32

48

24

REF

1

0

1

75.9

37.5

32

48

24

REF

1

1

0

83.3

41.7

32

48

24

REF

1

1

1

68.5

34.25

32

48

24

REF

VDD Groups:

VDD1 = X1, X2, REF/BSEL

VDD2 = CPU1-6

VDD3 = CPU7-8 & PLL Core

VDD4 = BUS1-6

VDD5 = 48/24 MHz

Latched Inputs:

L1 = BSEL

L2 = FS0

L3 = FS1

L4 = FS2

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.