ICS9248-72 Datasheet, PDF (2/12 Pages) Integrated Circuit Systems – Frequency Timing Generator for PENTIUM II Systems

ICS9248-72
Preliminary Product Preview
Power Groups:
VDDREF, GNDREF = REF, X1, X2
GNDPCI, VDDPCI = PCICLK
VDD66, GND66 = 3V66
VDD48, GND48 = 48MHz
VDDCOR, GNDCOR = PLL Core
VDDLCPU/2 , GNDLCPU/2 = CPU/2
VDDLIOAPIC, GNDIOAPIC = IOAPIC
Pin Descriptions
Pin number
1, 45, 46
2
3, 24, 29, 33
4
5
6, 14, 20, 26, 32
8, 7
9,17
19, 18, 16, 15, 13,
12, 11, 10
23, 22, 21
Pin name
IOAPIC[2:0]
REF0
VDD
X1
X2
GND
FS [2:1]
PCICLK [1:0]
VDDPCI
PCICLK [9:2]
3V66
25
SEL 133/100#
27
28
30
31
34
36, 35
37, 40
41
42
43
47
48
FS0
48 MHz
SEL24/48
24_48MHz#
SCLK
PD#
SDATA
CPUCLK [1:0]
VDDLCPU
GNDLCPU/2
CPU/2
VDDLCPU/2
GNDLIOAPIC
GNDREF
Type
Output
Output
Power
Input
Output
Power
IN
Output
Power
Description
2.5V IOAPIC clock outputs
3.3V, 14.318 MHz reference clock output.
3.3 V power
14.318 MHz crystal input
14.318 MHz crystal output
Ground
Frequency select pins. Latched Inputs determins the CPU & PCI frequencies.
3.3 V PCI clock outputs, generating timing requirements for
3.3 V power for the PCI clock outputs
Output 3.3 V PCI clock outputs
Output 3.3 V 66 MHz clock output, fixed frequency clock typically used with AGP
Input
control for the frequency of clocks at the CPU output pins. If logic "0" is used the
100 MHz frequency is selected. If Logic "1" is used, the 133 MHz frequency is
selected. The PCI clock is multiplexed to run at 33.3 MHz for both selected cases.
IN
Output
IN
Output
IN
Input
IN
0utput
Power
Power
Output
Power
Power
Power
Frequency select pin. Latched Inputs determins the CPU & PCI frequencies.
3.3 V 48 MHz clock output, fixed frequency clock typically used with USB
devices
48/24 MHz select option. Active low = 48 MHz output. Active High = 24
MHz
3.3V 48 or 24 MHz clock output, fixed frequency clock typically used with
USB devices.
Clock input of I2C input
Asynchronous active low input pin used to power down the device into a low
power state. The internal clocks are disabled and the VCO and the crystal are
stopped.
Data input for I²C serial input.
2.5 V CPU and Host clock outputs
2.5 V power for the CPU and Host clock outputs
Ground for the CPU and Host clock outputs
output running at 1/2 CPU clock frequency.Synchronous to the CPU outputs.
2.5 V power for the CPU/2 clock outputs
Ground for IOAPIC clocks
Ground for 14.318 MHz reference clock outputs
2