ICS9248-96 Datasheet, PDF (1/12 Pages) Integrated Circuit Systems – Frequency Generator & Integrated Buffers for Celeron & PII/III™

Integrated
Circuit
Systems, Inc.
ICS9248-96
Frequency Generator & Integrated Buffers for Celeron & PII/III™
Recommended Application:
810/810E type chipset.
Output Features:
• 2- CPUs @ 2.5V, up to 166.5MHz.
• 9 - SDRAM @ 3.3V, up to 155MHz including
1 free running
• 8 - PCICLK @ 3.3V
• 1 - IOAPIC @ 2.5V,
• 2 - 3V66MHz @ 3.3V, 2X PCI MHz
• 2 - 48MHz, @ 3.3V fixed.
• 1 - 24/48MHz, @3.3V selectable by I²C
• 1 - REF @v3.3V, 14.318MHz.
Features:
• Up to 166.5MHz 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).
• Uses external 14.318MHz crystal
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 table.
Pin Configuration
48-Pin 300mil SSOP
* These inputs have a 120K pull up to VDD.
** 60K pull-up to VDD on indicated input
1 These are double strength.
Block Diagram
Functionality
FS3 FS2
FS1 FS0
CPU
(MHz)
SDRAM
(MHz)
0 0 0 0 66.80 100.20
0 0 0 1 68.00 102.00
0 0 1 0 100.30 100.30
0 0 1 1 103.00 103.00
0 1 0 0 133.73 100.30
0 1 0 1 145.00 108.75
0 1 1 0 133.73 100.30
0 1 1 1 137.33 103.00
1 0 0 0 140.00 105.00
1 0 0 1 140.00 140.00
1 0 1 0 118.00 118.00
1 0 1 1 124.00 124.00
1 1 0 0 133.70 133.70
1 1 0 1 137.00 137.00
1 1 1 0 150.00 112.50
1 1 1 1 72.50 108.75
3V66
(MHz)
66.80
68.00
66.87
68.67
66.87
72.50
66.87
68.67
70.00
93.33
78.67
82.67
89.13
91.33
75.00
72.50
PCICLK
(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
IOAPIC
1=PCICLK/2
(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
IOAPIC
0=PCICLK
(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
Additional frequencies selectable through I²C
programming.
0311D—04/23/04