Datasheet AV9169CM-271, AV9169CJ-271, ICS9169CM-271 Datasheet (ICST)

Integrated
Circuit
Systems, Inc.

General Description Features

ICS9169C-271

Block Diagram

Frequency Generator for Pentium™ Based Systems

9169C-271RevC060297P

Pin Configuration

The ICS9169C-271 is a low-cost frequency generator
designed specifically for Pentium 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 68.5MHz is av ailable
for Turbo-mode of the 66.8MHz CPU. The ICS9169C-271
contains 12 CPU clocks, 4 PCI clocks, 1 REF at 48MHz and 1 at
24MHz.

The twelve CPU clock outputs provide sufficient clocks for
the CPU, chip set, memory and up to two DIMM connectors
(with four clocks to each DIMM). Either synchronous(CPU/

2) or asynchronous (32 MHz) PCI bus operation can be selected
by latching data on the BSEL input.

32-Pin SOIC/SOJ

Functionality

3.3V±10%, 0-70°C
Crystal (X1, X2) = 14.31818 MHz

Pentium is a trademark of Intel Corporation.

• Twelve selectable CPU clocks operate up to 83.3MHz

• Maximum CPU jitter of ± 200ps

• Six BUS clocks support sync or async bus operation

• ±250ps skew for all synchronous clock edges

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

• Integrated buffer outputs drive up to 30pF loads

• 3.0V - 3.7V supply range, CPU(1:12) outputs

2.5V(2.375-2.62V) VDD option

• 32-pin SOIC/SOJ package

• Logic inputs latched at Power-On for frequency
selection saving pins as Input/Output

• 48 MHz clock for USB support and 24 MHz clock
for FD.

ADDRESS

SELECT

CPU(1:12)

(MHz)

BUS (1:6)M Hz

48MHz 24MHz REF

FS2 FS1 FS0 BSEL=1 BSEL=0

00 0 50 25 32 48 24 REF
00 1 60 30 32 48 24 REF
0 1 0 66.8 33.4 32 48 24 REF
0 1 1 75.9 32 32 48 24 REF
1 0 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:

VDD = X1, X2, REF/BSEL
VDDC1 = CPU1-6
VDDC2 = CPU7-12 & PLL Core
VDDB = BUS1-6
VDDF = 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.

2

ICS9169C-271

Pin Descriptions

* The internal pull up will vary from 350K to 500K based on temperature

PIN NUMBER PIN NAME TYPE DESCRIPTION

1 VDD PWR

Power for device logic and crystal oscillator circuit and

14.318 MHz output.

2X1 IN

XTAL or external reference frequency input. This input
includes XTAL load capacitance and feedback bias for a
12-16MHz crystal, nominally 14.31818MHz External crystal
load of 30pF to GND recommended for VDD power on faster
than 2.0ms.

3 X2 OUT

XTAL output which includes XTAL load capacitance.
External crystal load of 10pF to GND recommended for VDD
power on faster than 2.0ms.

4,11,20,26 GND PWR Ground for device logic.

5

CPU(1) OUT

Processor clock output which is a multiple of the input
reference frequency.

FS0 IN Frequency multiplier select pins. 350K internal pull up.

6,7,9,10,15,16,17,18,19

CPU
(2:5) (8:12)

OUT

Processor clock outputs which are a multiple of the input
reference frequency.

8

VDDC1 PWR

Power for CPU(1:6) output buffers only. Can be reduced VDD
for 2.5V (2.375-2.62V) next generation processor clocks.

12

CPU(6) OUT

Processor clock output which is a multiple of the input
reference frequency internal pull up devices.

FS1 IN

Frequency multiplier select pin. See shared pin description.
350K internal pull up.

13

CPU(7) OUT

Processor clock output which is a multiple of the input
reference frequency internal pull up devices.

FS2 IN

Frequency multiplier select pin. See shared pin description.
350K internal pull up.

14 VDDC2 PWR

Power for CPU PLL, logic and CPU(7:12)output buffers. Must
be nominal 3.3V (3.0 to 3.7V)

21,22,24,25,27,28 BUS (1:6) OUT

BUS clock outputs which are a multiple of the input

reference clock.
23 VDDB PWR Power for BUS clock buffers BUS(1:6).
29 VDDF PWR Power for fixed clock buffer (48 MHz, 24 Mhz).

30 24MHz OUT

Fixed 24MHz clock (assuming a 14.31818MHz REF

frequency).
31 48MHz OUT

Fixed 48MHz clock (assuming a 14.31818MHz

REF frequency).

32

REF OUT

Fixed 14.31818MHz clock (assuming a 14.31818MHz

REF frequency).

BSEL IN

Selection for synchronous or asynchronous bus clock

operation. See shared pin programming description late in this

data sheet for further explanation. 350K internal pull up.

3

ICS9169C-271

The ICS9169C-271 includes a production test verification
mode of operation. This requires that the FS0 and FS1 pins
be programmed to a logic high and the FS2 pin be
programmed to a logic low(see Shared Pin Operation section).
In this mode the device will output the following
frequencies.

Note: REF is the frequency of either the crystal connected
between the devices X1and X2 or, in the case of a device
being driven by an external reference clock, the frequency
of the reference (or test) clock on the device’s X1 pin.

Shared Pin Operation - Input/Output Pins 5, 12, 13 and 32
on the ICS9169C-271 serve as dual signal functions to the
device. During initial power-up, they act as input pins. The
logic level (voltage) that is present on these pins at this time
is read and stored into a 4-bit internal data latch. At the end
of Power-On reset, (see AC characteristics for timing v alues),
the device changes the mode of operation for these pins to
an output function. In this mode the pins produce the
specified buffered clocks to external loads.

To program (load) the internal configuration register for
these pins, a resistor is connected to either the VDD (logic 1)
power supply or the GND (logic 0) voltage potential. A 10
Kilohm(10K) resistor is used to provide both the solid CMOS
programming voltage needed during the power-up
programming period and to provide an insignificant load on
the output clock during the subsequent operating period.

Figs. 1 and 2 show the recommended means of implementing
this function. In Fig. 1 either one of the resistors is loaded
onto the board (selective stuff ing) to configure the device’s
internal logic. Figs. 2a and b provide a single resistor loading
option where either solder spot tabs or a physical jumper
header may be used.
These figures illustrate the optimal PCB physical layout
options. These configuration resistors are of such a large
ohmic value that they do not effect the low impedance clock
signals. The layouts have been optimized to provide as little
impedance transition to the clock signal as possible, as it
passes through the programming resistor pad(s).

Shared Pin Operation ­Input/Output Pins

Test Mode Operation

Pin Frequency

REF REF
48MHz REF/2
24MHz REF/4

CPU (1:12) REF2

BUS (1:6)

BSEL=1 REF/4
BSEL = 0 REF/3

Fig. 1

(Resistors are surface mount devices
shown schematically between 5.m. pads)

*use only one programming resistor

4

ICS9169C-271

Fig. 2a

Fig. 2b

Fig. 3

5

ICS9169C-271

T echnical Pin Function Descriptions

VDD

This is the power supply to the internal logic of the device as
well as the following clock output buffers:

A. REF clock output buffers
B. BUS clock output buffers
C. Fixed clock output buffers

This pin may be operated at any voltage between 3.0 and 5.5
volts. Clocks from the listed buffers that it supplies will
have a voltage swing from ground to this level. For the
actual guaranteed high and low voltage levels of these
clocks, please consult the AC parameter table in this data
sheet.

GND

This is the power supply ground return pin for the internal
logic of the device as well as the following clock output
buffers:

A. REF clock output buffers
B. BUS clock output buffers
C. CPU clock output buffers
D. Fixed clock output buffers

X1

This pin serves one of two functions. When the device is
used with a crystal, X1 acts as the input pin for the reference
signal that comes from the discrete crystal. When the device
is driven by an external clock signal, X1 is the device’ input
pin for that reference clock. This pin also implements an
internal crystal loading capacitor that is connected to ground.
See the data tables for the value of the capacitor.

X2

This pin is used only when the device uses a Crystal as the
reference frequency source. In this mode of operation, X2 is
an output signal that drives (or excites) the discrete crystal.
This pin also implements an internal crystal loading capacitor
that is connected to ground. See the data tables for the value
of the capacitor.

CPU

This pin is the clock output that drives processor and other
CPU related circuitry that require clocks which are in tight
skew tolerance with the CPU clock. The voltage swing of
these clocks is controlled by that which is applied to the
VDDC pins of the device. See note on VDDC (1:2). See the
Functionality table at the beginning of this data sheet for a
list of the specific frequencies that this clock operates at and
the selection codes that are necessary to produce these
frequencies.

BUS

This pin is the clock output that is intended to drive the
systems plug-in card bus. The voltage swing of these

clocks is control-led by the supply that is applied to the
VDD pin of the device. See the Functionality table at the
beginning of this data sheet for a list of the specific
frequencies that this clock operates at and the selection
codes that are necessary to produce these frequencies.

FS0, FS1, FS2

These pins control the frequency of the clocks at the CPU,
CPUL, BUS & SDRAM pins. See the Funtionality table at
the beginning of this data sheet for a list of the specific
frequencies that this clock operates at and the selection
codes that are necessary to produce these frequencies. The
device reads these pins at power-up and stores the
programmed selection code in an internal data latch. (See
programming section of this data sheet for configuration
circuitry recommendations.

BSEL

This pin controls whether the BUS clocks will be synchronous
(run at half the frequency) with the CPU and CPUL clocks or
whether they will be asynchronous (run at a pre-programmed
fixed frequency) clock rate. It is a shared pin and is pro
grammed the same way as the frequency select pins.

VDDC (1:2)

These are the power supply pins for the CPU (1:6) and CPU
(7:12) clock buffers. By separating the clock power pins,
each group can receive the appropriate power decoupling
and bypassing necessary to minimize EMI and crosstalk
between the individual signals. VDDC1 can be reduced to

2.5V VDD for advanced processor clocks, which will bring
CPU (1:6) outputs at 0 to 2.5V output swings.

48 MHz

This is a fixed frequency clock that is typically used to drive
Super I/O peripheral device needs.

24 MHz

This is a fixed frequency clock that is typically used to drive
Keyboard controller clock needs.

REF

This is a fixed frequency clock that runs at the same frequency
as the input reference clock (typically 14.31818 MHz) is
and typically used to drive Video and ISA BUS
requirements.

VDDB

This power pin supplies the BUS clock buffers.

VDDF

This power pin supplies the 48/24 MHz clocks.

6

ICS9169C-271

Absolute Maximum Ratings

Electrical Characteristics at 3.3V

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 7.0 V

Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . GND –0.5 V to VDD +0.5 V

Ambient Operating Temperature . . . . . . . . . . . . 0°C to +70°C

Storage Temperature. . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C

VDD = 3.0 – 3.7 V, TA = 0 – 70°C unless otherwise stated

Note 1: Parameter is guaranteed by design and characterization. Not 100% tested in production.

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are
stress specifications only and functional operation of the device at these or any other conditions above those listed in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may affect product reliability.

DC Characteristics

PAR AMET ER SYM BOL TEST CO NDITION S MIN TYP MAX UN ITS

Input Low Voltage V

IL

- - 0.2V

DD

V

Input High Voltage V

IH

0.7V

DD

--V

Input Low Current I

IL

VIN=0V -28 .0 - 10.5 - µ A

Input High Current I

IH

VIN=V

DD

-5.0 - 5.0 µA

Ou tput Low C urre nt

1

I

OL

VOL=0.8V; for CPU, BUS,
Fixed CLKs

16.0 25.0 - mA

Output High Current

1

I

OH

VOL=2.0V; for CPU, BUS,
Fixed CLKs

- -30 .0 - 14.0 mA

Ou tput Low C urre nt

1

I

OL

VOL=0.8V; for REF CLK 19.0 3 0.0 - mA

Output High Current

1

I

OH

VOL=2.0V; for REF CLK - -38.0 -16.0 mA

Output Low Vo ltage

1

V

OL

I

OL

= 8mA; for CPU, BUS,

Fixed CLKs

-0.30.4V

Output High Voltage

1

V

OH

I

OH

= -8mA; for CPU, BUS,

Fixed CLKs

2.4 2.8 - V

Output Low Vo ltage

1

V

OL

I

OL

= 10 m A; for RE F C LK - 0 .3 0.4 V

Output High Voltage

1

V

OH

I

OH

= -15mA; for REF CLK 2.4 2.8 - V

Supply Current I

DD

@66.6 M Hz; all outputs unloaded - 90 180 mA

7

ICS9169C-271

Electrical Characteristics at 3.3V

VDD = 3.0 – 3.7 V, TA = 0 – 70°C unless otherwise stated

Note 1: Parameter is guaranteed by design and characterization. Not 100% tested in production.

AC Characteristics

PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNITS

Rise Time

1

T

r1

20pF load, 0.8 to 2.0V
CPU & BUS

- 0.9 1.5 ns

Fall Time

1

T

f1

20pF load, 2.0 to 0.8V
CPU & BUS

- 0.8 1.4 ns

Rise Time

1

T

r2

20pF load, 20% to 80%
CPU & BUS

- 1.5 2.5 ns

Fall Time

1

T

f2

20pF load, 80% to 20%
CPU & BUS

- 1.4 2.4 ns

Duty Cycle

1

D

t

20pF load @ V

OUT

=1.4V 455060%

Jitter, One Sigma

1

T

j1s 1

CPU & BUS Clocks; Load=20pF,
BSEL=1

- 50 150 ps

Jitter, Absolute

1

T

jab1

CPU & BUS Clocks; Load=20pF,
BSEL=1

-250 - 250 ps

Jitter, One Sigma

1

T

j1s 2

REF & Fixed CLKs; Load=20pF - 1 3 %

Jitter, Absolute

1

T

jab2

REF & Fixed CLKs; Load=20pF -5 2 5 %

Input Frequency

1

F

i

12.0 14.318 16.0 MHz

Logic Input Capacitance

1

C

IN

Logic input pins - 5 - pF

Crystal Oscillator Capacitance

1

C

INX

X1, X2 pins - 18 - pF

Power-on Time

1

t

on

From VDD=1.6V to 1st crossing of

66.6 MHz V

DD

supply ramp < 40ms

- 2.5 4.5 ms

Clock Skew

1

T

sk1

CPU to CPU; Load=20pF; @1.4V - 150 250 ps

Clock Skew

1

T

sk2

BUS to BUS; Load=20pF; @1.4V - 160 500 ps

Clock Skew

1

T

sk3

CPU to BUS; Load=20pF; @1.4V
(CPU is early)

1 2.2 4 ns

Clock Skew

1

T

sk4

CPU (@3.3V) to CPU (@2.5V)
(2.5V CPU is late)

0.5 1 ns

8

ICS9169C-271

SOIC P ackage

Ordering Information

ICS9169CM-271
ICS9169CJ-271

Pattern Number (2 or 3 digit number for parts with ROM code patterns)
Package Type

M=SOIC
J=SOJ

Device Type (consists of 3 or 4 digit numbers)
Prefix

ICS, AV = Standard Device

Example:

ICS XXXX M - PPP

SOJ Packa ge

0.818

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.