ICS9250-28 Datasheet, PDF (1/17 Pages) Integrated Circuit Systems – Frequency Generator & Integrated Buffers for Celeron & PII/III™

Integrated
Circuit
Systems, Inc.
ICS9250-28
Frequency Generator & Integrated Buffers for Celeron & PII/III™
Recommended Application:
810/810E and 815 type chipset.
Output Features:
• 2 CPU (2.5V) (up to 133MHz achievable through I²C)
• 13 SDRAM (3.3V) (up to 133MHz achievable
through I²C)
• 2 PCI (3.3 V) @33.3MHz
• 1 IOAPIC (2.5V) @ 33.3 MHz
• 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.
• I²C support for power management
• Efficient power management scheme through PD#
• Uses external 14.138 MHz crystal
• Alternate frequency selections available through I²C
control.
Pin Configuration
IOAPIC
1
VDDL
2
GND
3
*FS1/REF0
4
VDDREF
5
X1
6
X2
7
GND
8
VDD3V66
9
3V66_0
10
3V66_1
11
3V66_2
12
GND
13
VDDPCI
14
PCICLK0
15
PCICLK1
16
GND
17
FS0
18
GND
19
VDDA
20
PD#
21
SCLK
22
SDATA
23
GND
24
VDD48
25
48MHz_0
26
48MHz_1
27
FS2
28
56
VDDL
55
GND
54
CPUCLK0
53
CPUCLK1
52
GND
51
SDRAM0
50
SDRAM1
49
VDDSDR
48
GND
47
SDRAM2
46
SDRAM3
45
SDRAM4
44
VDDSDR
43
GND
42
SDRAM5
41
SDRAM6
40
VDDSDR
39
GND
38
SDRAM7
37
SDRAM8
36
SDRAM9
35
VDDSDR
34
GND
33
SDRAM10
32
SDRAM11
31
VDDSDR
30
GND
29
SDRAM12
56-Pin 300mil SSOP
* This input has a 50KW pull-down to GND.
Block Diagram
X1
XTAL
X2
OSC
PLL1
Spread
Spectrum
/2 /3
FS(2:0)
PD#
SDATA
SCLK
Control
Logic
Config
Reg
PLL2
/2
/2
Functionality
FS2 FS0 FS1
Function
0
0
X Tristate
0
1
X Test
REF0
1
0
0
Active CPU = 66MHz
SDRAM = 100MHz
1
1
0
Active CPU = 100MHz
SDRAM = 100MHz
2 ^{CPU66/100/133 [1:0]}
1
0
1
Active CPU = 133MHz
SDRAM = 133MHz
3V66 (2:0)
3
SDRAM (12:0)
13
1
1
1
Active CPU = 133MHz
SDRAM = 100MHz
PCICLK (1:0)
2
IOAPIC
2 ^{48MHz (1:0)}
Power Groups
Analog
VDDREF = X1, X2
VDDA = PLL1
VDD48 = PLL2
Digital
VDD3V66, VDDPCI
VDDSDR, VDDL
9250-28 Rev B 10/26/00
Third party brands and names are the property of their respective owners.
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.