ICS950208 Datasheet, PDF (2/19 Pages) Integrated Circuit Systems – Programmable Timing Control Hub for P4

Integrated
Circuit
Systems, Inc.
ICS950208
General Description
The ICS950208 is a single chip clock solution for desktop designs using the Intel Brookdale chipset with PC133 or DDR
memory. It provides all necessary clock signals for such a system.
The ICS950208 is part of a whole new line of ICS clock generators and buffers called TCH™ (Timing Control Hub). ICS is the
first to introduce a whole product line which offers full programmability and flexibility on a single clock device. This part
incorporates ICS's newest clock technology which offers more robust features and functionality. Employing the use of a
serially programmable I²C interface, this device can adjust the output clocks by configuring the frequency setting, the output
divider ratios, selecting the ideal spread percentage, the output skew, the output strength, and enabling/disabling each
individual output clock. TCH also incorporates ICS's Watchdog Timer technology and a reset feature to provide a safe setting
under unstable system conditions. M/N control can configure output frequency with resolution up to 0.1MHz increment. With
all these programmable features ICS's, TCH makes mother board testing, tuning and improvement very simple.
Pin Description
PIN
PIN
PIN
#
NAME
TYPE
DESCRIPTION
1
*MULTSEL1/REF1
I/O
3.3V LVTTL input for selection the current multiplier for CPU outputs / 14.318 MHz reference
clock.
2
VDDREF
PWR Ref, XTAL power supply, nominal 3.3V
3
X1
IN Crystal input, Nominally 14.318MHz.
4
X2
OUT Crystal output, Nominally 14.318MHz
5
GND
PWR Ground pin.
6
*FS2/PCICLK_F0
I/O Frequency select latch input pin / 3.3V PCI free running clock output.
7
*FS3/PCICLK_F1
I/O Frequency select latch input pin / 3.3V PCI free running clock output.
8
PCICLK_F2
OUT Free running PCI clock not affected by PCI_STOP# .
9
VDDPCI
PWR Power supply for PCI clocks, nominal 3.3V
10
*FS4/PCICLK0
#N/A #N/A
11
PCICLK1
OUT PCI clock output.
12
PCICLK2
OUT PCI clock output.
13
GND
PWR Ground pin.
14
PCICLK3
OUT PCI clock output.
15
PCICLK4
OUT PCI clock output.
16
PCICLK5
OUT PCI clock output.
17
PCICLK6
OUT PCI clock output.
18
VDDPCI
PWR Power supply for PCI clocks, nominal 3.3V
19
Vttpwr_GD#
IN ^{This 3.3V LVTTL input is a level sensitive strobe used to determine when latch inputs are}
valid and are ready to be sampled. This is an active low input.
20
RESET#
OUT
Real time system reset signal for frequency gear ratio change or watchdog timer timeout.
This signal is active low.
21
GND
PWR Ground pin.
22
*FS0/48MHz
I/O Frequency select latch input pin / Fixed 48MHz clock output. 3.3V
23
*FS1/24_48MHz
I/O Frequency select latch input pin / Fixed 24 or 48MHz clock output. 3.3V.
24
AVDD48
PWR Power for 24/48MHz outputs and fixed PLL core, nominal 3.3V
* Internal Pull-Up Resistor
** Internal Pull-Down Resistor
~ This output has 2X drive
0464B—08/04/03
2