Integrated

Circuit

Systems, Inc.

General Description

Features

ICS9147-09

Block Diagram

Pentium is a trademark of Intel Corporation

Frequency Generator & Integrated Buffers for 686 Series CPUs

9147-09 Rev A 10/2897P

Pin Configuration

The ICS9147-09 generates all clocks required for high

speed RISC or CISC microprocessor systems such as Intel

PentiumPro,AMD or Cyrix processors. Four bidirectional I/O

pins (FS0, FS1, FS2, BSEL) are latched at power-on to the

functionality table. The Six BUS clocks can be selected as

either synchronous at 1/2 CPU speed or asynchronous at

32MHz selected by BSEL latched input.The inputs provide

for tristate and test mode conditions to aid in system level

testing.These multiplying factors can be customized for

specific applications. Glitch-free stop clock controls

provided for CPU.

High drive BUS and SDRAM outputs typically provide

greater than 1 V/ns slew rate into 30 pF loads. CPU outputs

typically provide better than 1V/ns slew rate into 20pF

loads while maintaining 50±5% duty cycle. The REF clock

outputs typically provide better than 0.5V/ns slew rates.

Seperate buffer supply pin VDDL allows for nominal 3.3V

voltage or reduced voltage swing (from 2.9 to 2.5V) for

CPUL (1:2) and IOAPIC outputs.

•

Total of 15 CPU speed clocks:

- Two copies of CPU clock with VDDL (2.5 to 3.3V)

- Twelve (12) SDRAM (3.3v) plus one

CPUH/AGP (3.3V) clocks

•

Six copies of BUS clock (synchronous with CPU clock/2 or

asynchronous 32 MHz)

•

250ps output skew window for CPU andSDRAM clocks

and 500ps window BUS clocks. CPU clocks to

BUSclocks skew 1-4ns (CPU early)

•

Two copies of Ref. clock @14.31818 MHz (One driven

by VDDL as IOAPIC)

•

One 48 MHz (3.3 V TTL) for USB support and single

24 MHz.

•

Separate VDDL for CPUL (1:2) clock buffers and

IOAPIC to allow 2.5V output (or Std. Vdd)

•

3.0V – 3.7V supply range w/2.5V compatible outputs

•

48-pin SSOP package

48-Pin SSOP

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.