Integrated
Circuit
Systems, Inc.
ICS9250-28
Frequency Generator & Integrated Buffers for Celeron & PII/III™
Recommended Application:
Pin Configuration
810/810E and 815 type chipset.
IOAPIC
VDDL
GND
1
2
56
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
VDDL
GND
Output Features:
2 CPU (2.5V) (up to 133MHz achievable through I2C)
3
4
5
6
7
8
9
CPUCLK0
CPUCLK1
GND
SDRAM0
SDRAM1
VDDSDR
GND
SDRAM2
SDRAM3
SDRAM4
VDDSDR
GND
SDRAM5
SDRAM6
VDDSDR
GND
SDRAM7
SDRAM8
SDRAM9
VDDSDR
GND
SDRAM10
SDRAM11
VDDSDR
GND
•
•
*FS1/REF0
VDDREF
X1
13 SDRAM (3.3V) (up to 133MHz achievable
through I2C)
X2
GND
•
•
•
•
•
2 PCI (3.3 V) @33.3MHz
VDD3V66
3V66_0
3V66_1
3V66_2
GND
VDDPCI
PCICLK0
PCICLK1
GND
1 IOAPIC (2.5V) @ 33.3 MHz
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
3 Hublink clocks (3.3 V) @ 66.6 MHz
2 (3.3V) @ 48 MHz (Non spread spectrum)
1 REF (3.3V) @ 14.318 MHz
Features:
•
Supports spread spectrum modulation,
0 to -0.5% down spread.
FS0
GND
VDDA
PD#
•
•
•
•
I2C support for power management
Efficient power management scheme through PD#
Uses external 14.138 MHz crystal
Alternate frequency selections available through I2C
control.
SCLK
SDATA
GND
VDD48
48MHz_0
48MHz_1
FS2
SDRAM12
56-Pin 300mil SSOP
* This input has a 50KW pull-down to GND.
Functionality
Block Diagram
FS2
FS0
FS1
Function
0
0
0
1
X
X
Tristate
Test
X1
X2
XTAL
OSC
REF0
Active CPU = 66MHz
SDRAM = 100MHz
1
1
1
1
0
1
0
1
0
0
1
1
PLL1
Spread
Spectrum
Active CPU = 100MHz
SDRAM = 100MHz
/2
/3
Active CPU = 133MHz
SDRAM = 133MHz
CPU66/100/133 [1:0]
2
3V66 (2:0)
FS(2:0)
PD#
3
Control
Logic
Active CPU = 133MHz
SDRAM = 100MHz
SDRAM (12:0)
13
Config
Reg
PCICLK (1:0)
IOAPIC
/2
2
SDATA
SCLK
Power Groups
/2
Analog
Digital
VDD3V66, VDDPCI
VDDSDR, VDDL
VDDREF = X1, X2
VDDA = PLL1
VDD48 = PLL2
48MHz (1:0)
PLL2
2
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
9250-28 Rev B 10/26/00
Third party brands and names are the property of their respective owners.
information being relied upon by the customer is current and accurate.