Integrated
Circuit
Systems, Inc.
ICS9248-65
Frequency Timing Generator for PENTIUM IISystems
Features
Generates the following system clocks:
- 3 CPU clocks ( 2.5V, 100/133MHz)
- 10 PCI clocks, including 1 free-running
(3.3V, 33.3MHz)
- 1 CPU/2 clocks (2.5V, 50/66.6MHz)
- 1 IOAPIC clocks (2.5V, 16.67MHz)
- 3 Fixed frequency 66MHz clocks(3.3V, 66.6MHz)
- 2 REF clocks(3.3V, 14.318MHz)
- 1 USB clock (3.3V, 48MHz)
Efficient power management through PD#.
0 to -0.5% typical down spread modulation on CPU, PCI,
IOAPIC, 3V66 and CPU/2 output clocks.
Uses external 14.318MHz crystal.
Key Specification
CPU Output Jitter: <250ps
CPU/2 Output Jitter. <250ps
IOAPIC Output Jitter: <500ps
48MHz, 3V66, PCI Output Jitter: <500ps
PCI Output Jitter. <500ps
Ref Output Jitter. <1000ps
CPU 0:2 Output Skew: <175ps
PCI_F, PCI 1:7 Output Skew: <500ps
3V66_0:2 Output Skew <250ps
CPU to 3V66_0:2 Output Offset: 0.0 - 1.5ns (CPU leads)
3V66 to PCI Output Offset: 1.5 - 4ns (CPU leads)
CPU to IOAPIC Output Offset 1.5 - 4.0ns (CPU leads)
Block Diagram
Pin Configuration
Third party brands and names are the property of their respective owners.
9248-65 Rev C 7/28/99
48-pin SSOP
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.