Integrated
Circuit
Systems, Inc.
ICS9147-14
Frequency Generator & Integrated Buffers for PENTIUM/Pro
TM
General Description
The
ICS9147-14
generates all clocks required for high speed
RISC or CISC microprocessor systems such as Intel
PentiumPro. Two bidirectional I/O pins (FS1,FS2) are latched
at power-on to the functionality table, with FS0 selectable in
real-time to toggle between conditions.
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Features
High drive PCICLK and SDRAM outputs typically provide
greater than 1 V/ns slew rate into 30 pF loads. CPU outputs
typically provide better than 1V/ns slew rate into 20 pF loads
while maintaining
50 鹵
5% duty cycle. The REF clock outputs
typically provide better than 0.5V/ns slew rates. Seperate
buffers supply pins VDDL1 allow for 3.3V or reduced voltage
swing (from 2.9 to 2.5V) for CPU (0:3) and IOAPIC outputs.
Block Diagram
Four copies of CPU clock
Twelve SDRAM (3.3V TTL), usable asAGP clocks
Seven copies of PCICLK clock (synchronous with CPU
clock/2 or CPU/2.5 for 75 and 83.3 MHz CPU)
CPU clocks to PCICLK clocks skew 1-4ns, center 2.6ns.
One IOAPIC clock @14.31818 MHz
Two copies of Ref. clock @14.31818 MHz
Ref. 14.31818 MHz Xtal oscillator input
Separate V
DDL1
for four CPU and single IOAPIC output
buffers to allow 2.5V output (or Std. Vdd)
One each 48/ 24MHz (3.3V TTL)
3.3V outputs: SDRAM, PCI, REF, 48/24MHz.
2.5V or 3.3V outputs: CPU, IOAPIC.
20 ohm CPU clock output impedance
20 ohm PCI clock output impedance
1.5ns rise time (30 pF loading)
鹵250 ps CPU, PCI clock skew
350ps (cycle by cycle) CPU jitter
2ms Power up clock stable time
45-55% Clock duty cycle
48 pin 300 mil SSOP package
3.0V 聳 3.7V supply range w/2.5V compatible outputs
Pin Configuration
Power Groups
VDD1 = REF (0:1), X1, X2, 24MHz, 48MHz
VDD2 = PCICLKF, PCICLK(0:5)
VDD3 = SDRAM (0;11)
VDDL1 = CPUCLK (0:3)
9147-14 Rev B 071897P
48-Pin SSOP
* Internal Pull-up Resistor of
300K to 3.3V on indicated inputs
Pentium is a trademark of Intel Corporation
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.
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