ICS9147-12 Integrated Circuit Systems, ICS9147-12 Datasheet - Page 2

• Manufacturer Part Number: ICS9147-12
• Description: Pentium/ProTM System Clock Chip
• Manufacturer: Integrated Circuit Systems

9, 11, 12, 13, 14, 16
3, 10, 17, 24, 31,
PIN NUMBER
26, 27, 29, 30,
32, 33, 35, 36
38, 39, 41, 42
31, 37, 43
25, 28,34
40, 46
6, 20,
7, 15
18
19
21
22
23
44
45
47
48
1
2
4
5
8
FS2
REF1
REF0
GND
X1
X2
N/C
VDD2
PCICLK_F
PCICLK (0:5)
FS0
FS1
VDD4
48MHz
24MHz
VDD3
SDRAM (0:7)
CPUCLK (0:3)
VDDL
PD#
IOAPIC
REF2
VDD1
PIN NAME
TYPE
PWR
PWR
PWR
PWR
PWR
PWR
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
IN
IN
IN
IN
IN
-
Latched input for frequency select2
Reference clock output
Reference clock output
Ground (common)
Crystal or reference input, nominally 14.318 MHz. Includes
internal load cap to GND and feedback resistor from X2.
Crystal output, includes internal load cap to GND.
Pins are not internally connected
Supply for PCICLK_F, and PCICLK (0:5)
Free running PCI clock
PCI clocks
Frequency select 0 input
Frequency select 1 input
Supply for 48MHz and 24MHz clocks
48MHz driver output for USB clock
24MHz driver output for Super I/O clock
Supply for SDRAM (0:7),
SDRAMs clock at CPU speed
CPUCLK clock output, powered by VDDL
Supply for CPUCLK (0:3) & IOAPIC
Power down stops all clocks low and disables oscillator and
internal VCO’s.
IOAPIC clock output, powered by VDDL at crystal frequency
Reference clock output.
Supply for REF (0:2), X1, X2
2
DESCRIPTION
1
1
1