Integrated
Circuit
Systems, Inc.
AV9155C-44
Low Cost 20-Pin Frequency Generator
General Description
The
AV9155C-44
is a low cost frequency generator designed
specifically for desktop and notebook PC applications with
either 3.3V or 5.0V power supply voltage. Its CPU clocks
provide all necessary CPU frequencies for 286, 386 and 486
systems, including support for the latest speeds of processors.
The device uses a 14.318 MHz crystal to generate the CPU
and all peripheral clocks for integrated desktop motherboards.
The dual 14.318 MHz clock outputs allows one output for the
system and one to be the input to an ICS graphics frequency
generator such as the AV9194.
The CPU clock offers the unique feature of smooth, glitch-
free transitions from one frequency to the next, making this
ideal device to use whenever slowing the CPU speed. The
AV9155C-44
makes a gradual transition between frequencies,
so that it obeys the Intel cycle-to-cycle timing specification
for 486 systems. The simultaneous 2X and 1X CPU clocks
offer controlled skew to within 1.5ns (max) of each other.
Features
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Compatible with 286, 386, and 486 CPUs
Supports turbo modes
Generates communications clock, keyboard clock,
floppy disk clock, system reference clock, bus clock
and CPU clock
Output enable tristates outputs
Up to 100 MHz at 5V or 3.3V
20-pin DIP or SOIC
All loop filter components internal
Skew-controlled 2X and 1X CPU clocks
Power-down option
Pin Configuration
Block Diagram
20-Pin DIP or SOIC
THIS DATA SHEET (AV9155C-44) IS AN ADDENDUM TO THE EXISTING AV9155C
DATA SHEET. ALL INFORMATION IN THIS DATA SHEET SUPERSEDES THE DATA
FOUND IN THE ORIGINAL AV9155C DATA SHEET.
9155-44 Rev D 02/12/98
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.
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