ICS9248-78 Datasheet, PDF (2/13 Pages) Integrated Circuit Systems – Frequency Timing Generator for Pentium II Systems

ICS9248 - 78
Preliminary Product Preview
Pin Descriptions
PIN
NUMBER
1
2, 9, 10, 18,
25, 29, 37
3
PIN NAME
REF1
VDD
X1
4
X2
5, 6, 14, 21, 28,
33, 41
GND
7, 8
3V66 (1:0)
PCICLK0¹
11
FS0
PCICLK1¹
12
FS1
13, 15, 16,
17, 19, 20
PCICLK (2:7)
22
PD#
23
SCLK
24
SDATA
48MHz
26
FS3
27
30
40, 39, 38, 36,
35, 34, 32, 31
42
FS2
24MHz
SDRAM_F
SDRAM (7:0)
GNDL
43, 44 CPUCLK (1:0)
45, 47
46
48
VDDL
IOAPIC
SEL_3V66
REF0¹
TYPE
DESCRIPTION
OUT 3.3V, 14.318MHz reference clock output.
PWR 3.3V power supply
IN
OUT
Crystal input, has internal load cap (33pF) and feedback
resistor from X2
Crystal output, nominally 14.318MHz. Has internal load
cap (33pF)
PWR Ground pins for 3.3V supply
OUT
OUT
IN
OUT
IN
3.3V clock outputs for HUB running at 2XPCI MHz
3.3V PCI clock outputs, with Synchronous CPUCLKS
Logic input frequency select bit. Input latched at power on.
3.3V PCI clock outputs, with Synchronous CPUCLKS
Logic input frequency select bit. Input latched at power on.
OUT 3.3V PCI clock outputs, with Synchronous CPUCLKS
Asynchronous active low input pin used to power down the device into
IN
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.
IN Clock input of I²C input
IN Data input for I²C serial input.
OUT 3.3V Fixed 48MHz clock output for USB
IN Logic input frequency select bit. Input latched at power on.
IN
OUT
OUT
Logic input frequency select bit. Input latched at power on.
3.3V fixed 24MHz output
3.3V free running SDRAM not affected by I²C
OUT 3.3V outputs
PWR
OUT
PWR
OUT
IN
OUT
Ground for 2.5V power supply for CPU & APIC
2.5V Host bus clock output.
2.5V power suypply for CPU, IOAPIC
2.5V clock outputs running at PCI/2 MHz
This pin selects the 3V66 output frequency.
3.3V, 14.318MHz reference clock output.
Note:
1. These pins will have 2X drive strength.
2