ICS9248-112 Datasheet, PDF (1/12 Pages) Integrated Circuit Systems – Frequency Generator & Integrated Buffers for Celeron & PII/III™

Integrated
Circuit
Systems, Inc.
ICS9248-112
Preliminary Product Preview
Frequency Generator & Integrated Buffers for Celeron & PII/III™
Recommended Application:
810/810E type chipset.
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
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.
Pin Configuration
48-Pin 300mil SSOP
* These inputs have a 120K pull up to VDD.
1 These are double strength.
Block Diagram
9248- 112 Rev A 2/7/00
Third party brands and names are the property of their respective owners.
Functionality
FS3 FS2 FS1 FS0
000 0
000 1
0010
001 1
0 10 0
0 10 1
0 110
0 11 1
100 0
100 1
10 10
10 1 1
1 10 0
1 10 1
1110
111 1
CPU SDRAM
(MHz) (MHz)
66.80
68.00
100.30
103.00
133.73
145.00
133.73
137.33
140.00
140.00
118.00
124.00
133.70
137.00
150.00
72.50
100.20
102.00
100.30
103.00
100.30
108.75
100.30
103.00
105.00
140.00
118.00
124.00
133.70
137.00
112.50
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.
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.