ICS9248-92 Datasheet, PDF (1/14 Pages) Integrated Circuit Systems – Mobile Pentium IITM System Clock Chip

Integrated
Circuit
Systems, Inc.
ICS9248-92
Mobile
Pentium
TM
II
System
Clock
Chip
Recommended Application:
The ICS9248-92 is a fully compliant timing solution for the
Intel mobile 440BX/MX chipset requirements.
General Description:
Features include two strong CPU, seven PCI and eight SDRAM
clocks. Three reference outputs are available equal to the
crystal frequency. Stronger drive CPUCLK outputs typically
provide greater than 1 V/ns slew rate into 20pF loads. This
device meets rise and fall requirements with 2 loads per CPU
output (ie, one clock to CPU and NB chipset, one clock to two
L2 cache inputs).
PWR_DWN# pin allows low power mode by stopping crystal
OSC and PLL stages. For optional power management,
CPU_STOP# can stop CPU (0:1) clocks and PCI_STOP# will
stop PCICLK (0:5) clocks
PCICLK outputs typically provide better than 1V/ns slew rate
into 30pF loads while maintaining 50±5% duty cycle. The REF
clock outputs typically provide better than 0.5V/ns slew rates.
The ICS9248-92 accepts a 14.318MHz reference crystal or
clock as its input and runs on a 3.3V core supply.
Features
• Generates system clocks for CPU, SDRAM, PCI, plus
14.318 MHz REF(0:2), USB, Plus Super I/O
• I²C serial configuration interface provides output clock
disabling and other functions
• MODE input pin selects optional power management
input control pins
• Two fixed outputs separately selectable as 24 or 48MHz
• 2.5V outputs: CPU
• 3.3V outputs: SDRAM, PCI, REF, 48/24 MHz
• No power supply sequence requirements
• Uses external 14.318MHz crystal
• 48 pin 240 mil TSSOP package
• Output enable register
for serial port control:
1 = enable
0 = disable
Block Diagram
Pin Configuration
Pentium is a trademark on Intel Corporation.
9248-92 Rev E 02/21/01
48-Pin TSSOP 240 mil Package
Functionality
Crystal (X1, X2) = 14.31818 MHz
SEL
100/66#
0
1
CPUCLK
(MHz)
66.6
100
PCICLK
(MHz)
33.3
33.3
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.