ICS9248-112
Integrated
Circuit
Systems, Inc.
Preliminary Product Preview
Frequency Generator & Integrated Buffers for Celeron & PII/III™
Recommended Application:
810/810E type chipset.
Pin Configuration
Output Features:
•
•
2- CPUs @2.5V, up to 150MHz.
9 - SDRAM @ 3.3V, up to150MHz including
1 free running
•
•
•
•
•
•
8 - PCICLK @ 3.3V
1 - IOAPIC @ 2.5V, PCI or PCI/2 MHz
2 - 3V66MHz @ 3.3V, 2X PCI MHz
1- 48MHz, @3.3V fixed.
1- 24MHz, @3.3V fixed
1- REF @3.3V, 14.318MHz.
Features:
•
•
•
Up to 166MHz frequency support
Support FS0-FS3 strapping status bit for I2C read back.
Support power management: Through Power down
Mode from I2C programming.
•
•
Spread spectrum for EMI control ( ± 0.25% center).
Spread can be enabled or disabled to all 32 frequencies
throuth I2C.
•
Uses external 14.318MHz crystal
48-Pin 300mil SSOP
* These inputs have a 120K pull up to VDD.
1 These are double strength.
Skew Specifications:
•
•
•
•
•
•
CPU – CPU: <175ps
SDRAM - SDRAM: < 250ps
3V66 – 3V66: <175ps
PCI – PCI: <500ps
CPU-SDRAM<500ps
For group skew specifications, please refer to group
timing relationship.
Block Diagram
Functionality
IOAPIC
1=PCICLK/2 0=PCICLK
IOAPIC
CPU
(MHz)
SDRAM
(MHz)
3V66
(MHz)
PCICLK
(MHz)
FS3 FS2 FS1 FS0
(MHz)
16.70
17.00
16.72
17.17
16.72
18.13
16.72
17.17
17.50
23.33
19.67
20.67
22.28
22.83
18.75
18.13
(MHz)
33.40
34.00
33.43
34.33
33.43
36.25
33.43
34.33
35.00
46.67
39.33
41.33
44.57
45.67
37.50
36.25
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
66.80 100.20 66.80
68.00 102.00 68.00
100.30 100.30 66.87
103.00 103.00 68.67
133.73 100.30 66.87
145.00 108.75 72.50
133.73 100.30 66.87
137.33 103.00 68.67
140.00 105.00 70.00
140.00 140.00 93.33
118.00 118.00 78.67
124.00 124.00 82.67
133.70 133.70 89.13
137.00 137.00 91.33
150.00 112.50 75.00
72.50 108.75 72.50
33.40
34.00
33.43
34.33
33.43
36.25
33.43
34.33
35.00
46.67
39.33
41.33
44.57
45.67
37.50
36.25
Additional frequencies selectable through I2C programming.
PRODUCT PREVIEW documents contain information on new
products in the sampling or preproduction phase of development.
Characteristic data and other specifications are subject to change
without notice.
9248- 112 Rev A 2/7/00
Third party brands and names are the property of their respective owners.