ics9248-61 Integrated Device Technology, ics9248-61 Datasheet - Page 2

• Manufacturer Part Number: ics9248-61
• Description: Frequency Timing Generator For Pentium Ii Systems
• Manufacturer: Integrated Device Technology

Pin Descriptions
ICS9248-61
Pin number
5,6,9,10, 11
23,24
1,27
12
13
14
15
16
17
18
19
20
21
22
25
26
28
2
3
4
7
8
SEL 100_66#/
CPUCLK (0:1)
CPU_STOP#
PCICLK (1:4)
Pin name
PCI-STOP#
PCICLK_E
PCICLK_F
GNDLCPU
VDDLCPU
SPREAD#
VDDCOR
REF(0:1)
GNDPCI
VDDPCI
GNDR/C
VDD48
GND48
48MHz
DIV4#
VDDR
PD#
X1
X2
Output
Output
Output
Output
Output
Output
Type
Power
Power
Power
Power
Power
Power
0utput
Input
Input
Input
Input
Input
Input
Input
Input
Input
14.318 MHz crystal input
14.318 MHz crystal output
3.3 V free running PCI clock output, will not be stopped by the PCI_STOP#
Ground for PCI clock outputs
3.3 V power for the PCI clock outputs
Early PCICLK output, offset from other PCICLKs, stopped by PCI-STOP#
3.3 V power for 48 MHz clocks
on power-on control for the frequency of clocks at the CPU & PCICLK output pins. If
logic "0" is used the 66.6 MHz frequency is selected. If Logic "1" is used, the 100
MHz frequency is selected. The PCI clock is multiplexed to run at 33.3 MHz for both
selects
Ground for 48 MHz clocks
Active low input, enables the CPUCLK and the PCICLK to run at 1/4 of the regular
frequecies
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. The
latency of the power down will not be greater than 3ms.
Asynchronous active low input pin used to stop the CPUCLK in active low state, all
other clocks will continue to run. The CPUCLK will have a "Turnon " latency of at
least 3 CPU clocks.
3.3 V power for the core
Synchronous active low input used to stop the PCICLK in active low state. It will not
effect PCICLK_F or any other outputs.
Ground for REFCLK, Crystal & Core
Ground for the CPU and Host clock outputs
2.5 V power for the CPU and Host clock outputs
enable. Active high = spread spectrum clocking disable.
3.3 V power for the REFCLK and crystal clock outputs
3.3V, 14.318 MHz reference clock output.
2.5 V CPU and Host clock outputs
3.3 V PCI clock outputs, generating timing requirements
power-on spread spectrum enable option. Active low = spread spectrum clocking
Description