Integrated
Circuit
Systems, Inc.
ICS9250-22
Frequency Generator for P IV™
Recommended Application:
P IV Chipset Support
Output Features:
Pin Configuration
GND
MULTSEL0/REF
MULTSEL1/REF
VDDREF
X1
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
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
VDDMREF
3VMREF
•
•
4 Differential CPU Clock Pairs @ 3.3V
2 - 3V MREF clocks for memory reference seeds,
(separate single ended but 180 degrees out of phase)
3VMREF_B
GNDMREF
SPREAD#
CPUCLKST3
CPUCLKSC3
VDDCPU
CPUCLKST2
CPUCLKSC2
GNDCPU
CPUCLKST1
CPUCLKSC1
VDDCPU
CPUCLKST0
CPUCLKSC0
GNDCPU
I REF
VDDA
GNDA
VDD3V66
3V66-3
3V66-2
GND3V66
GND3V66
3V66-1
3V66-0
VDD3V66
X2
•
•
•
4 - 66MHz reference output
10 - 3V 33MHz PCI clocks
2 - 48MHz clocks
GNDREF
PCICLK0
PCICLK1
VDDPCI
PCICLK2
PCICLK3
GNDPCI
PCICLK4
PCICLK5
VDDPCI
PCICLK6
PCICLK7
GNDPCI
PCICLK8
PCICLK9
VDDPCI
•
2 - 14.318 reference output
Features:
•
•
Support power management: Power Down Mode
Supports Spread Spectrum modulation: 0 to -0.5% down
spread.
•
•
Uses external 14.318MHz crystal
Select logic for Differential Swing Control, Test mode,
Tristate, Power down, Spread Spectrum, limited
frequency select, selective clock enable.
SEL100/133
GND48
FS0/48MHz
FS1/48MHz
VDD48
•
•
External resistor for current reference
FS pins for frequency select
Key Specifications:
PD#
•
•
•
3V66 Output jitter <300ps
CPU Output Jitter <200ps
MREF Output jitter <250ps
56-Pin 300mil SSOP &TSSOP
Block Diagram
Functionality
SEL133/
100
FS0 FS1
Function
0
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Active 100MHz
(Reserved)
PLL2
48MHz
2
0
0
(Reserved)
0
Tristate all outputs
Active 133MHz
(Reserved)
X1
X2
XTAL
OSC
REF
2
1
1
PLL1
Spread
Spectrum
CPUCLKST (3:0)
CPUCLKSC (3:0)
CPU
DIVDER
4
1
(Reserved)
4
1
Test Mode
3VMREF
DIVDER
3VMREF
3VMREF_B
Control
Logic
PD#
SPREAD#
PCI
DIVDER
PCICLK (9:0)
3V66 (3:0)
10
4
Power Groups
MULTSEL (1:0)
SEL100/133
FS(1:0)
Config.
Reg.
VDDREF, GNDREF=REF, X1, X2
3V66
DIVDER
VDDPCI, GNDPCI=PCICLK
VDD48, GND48=48MHz, PLL2
VDD3V66,GND3V66=3V66
VDDCPU, GNDCPU=CPUCLK
VDDMREF, GNDMREF=3VMREF, 3VMREF_B
VDDA=VDD (core supply voltage 3.3V)
GNDA=Ground for core supply
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
9250-22 Rev B 12/08/00
Third party brands and names are the property of their respective owners.
information being relied upon by the customer is current and accurate.