Integrated
Circuit
Systems, Inc.
ICS9250-18
Frequency Generator & Integrated Buffers for Celeron & PII/III™
Recommended Application:
Pin Configuration
BX, Appollo Pro 133 type of chip set.
VDDREF
*FS2/REF1
*PCI_STOP#/REF0
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
56
VDDLIOAPIC
IOAPIC0
IOAPIC_F
GND
CPUCLK_F
CPUCLK1
VDDLCPU
CPUCLK2
GND
CPU_STOP#
SDRAM_F
VDDSDR
SDRAM0
SDRAM1
GND
SDRAM2
SDRAM3
SDRAM4
SDRAM5
VDDSDR
SDRAM6
SDRAM7
GND
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
Output Features:
X1
X2
VDDPCI
•
•
•
•
•
•
•
3 - CPUs @2.5V, up to 166MHz.
17 - SDRAM @ 3.3V, up to 166MHz.
7 - PCI @3.3V
2 - IOAPIC @ 2.5V
1 - 48MHz, @3.3V fixed.
1 - 24MHz @ 3.3V
*MODE/PCICLK_F
*FS3/PCICLK0
GND
PCICLK1
PCICLK2
PCICLK3
PCICLK4
VDDPCI
PCICLK5
BUFFERIN
SDRAM11
SDRAM10
VDDSDR
SDRAM9
SDRAM8
GND
2 - REF @3.3V, 14.318MHz.
Features:
•
•
Up to 166MHz frequency support
Support power management: CPU, PCI, stop and
Power down Mode form I2C programming.
•
•
Spread spectrum for EMI control ( 0.25ꢀ center
spread)
Uses external 14.318MHz crystal
SDRAM15
SDRAM14
GND
SDRAM12
SDRAM13
VDD48
24MHz/FS0*
48MHz/FSI*1
SDATA
SCLK
I2C
{
Key Specifications:
•
•
•
•
CPU – CPU: <175ps
CPU – PCI: 1 - 4ns
PCI – PCI: <500ps
56-Pin SSOP
* Internal Pull-up Resistor of 240K to 3.3V on indicated inputs
** Internal Pull-down resistor of 240K to GND on indicated
inputs. 1. This output is double strength.
SDRAM - SDRAM: <250ps
Block Diagram
Functionality
CPU
(MHz)
80.00
75.00
83.31
PCICLK
(MHz)
40.00
37.50
41.65
33.45
34.33
37.34
34.01
33.57
40.00
38.33
36.66
35.00
35.00
37.50
31.00
33.25
FS3
FS2
FS1
FS0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
66.9
103.00
112.01
68.01
100.7
120.00
114.99
109.99
105.00
140.00
150.00
124.00
133.9
0387C—09/08/05
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.