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ADVANCED INFORMATION
describes products that are not in full production at the time of printing. Specifications are based on design goals
and limited characterization. They may change without notice. Contact Fairchild Semiconductor for current information.
www.fairchildsemi.com
Features
Maximized EMI suppression using Fairchild’s proprietary
Spread Spectrum Technology
Single chip system frequency synthesizer for Intel BX
chip set
Two copies of CPU output
Six copies of PCI output
One 48MHz output for USB
One 24MHz output for SIO
Two buffered reference outputs
One IOAPIC output
Fourteen SDRAM outputs provide support for 3 DIMMs
Supports frequencies up to 150MHz
I
2
C interface for programming
Power management control inputs
Smooth CPU frequency switching from 66.8
Description
The RC7102 was developed as a single chip device to meet
the clocking needs of the Intel BX chipset. In addition to
the typical outputs provided by standard 100 MHz BX
FTG’s, the RC7102 adds a fourteen output buffer, supporting
SDRAM DIMM modules in conjunction with the chipset.
Fairchild’s proprietary spread spectrum frequency synthesis
technique is a feature of the CPU and PCI outputs. When
enabled, this feature reduces the peak EMI measurements by
up to 10dB.
RC7102
BX S pread S pec trum Frequenc y S ynthesizer for
Pentium II
Block Diagram
XTAL
OSC
REF0
REF1/FS2
IOAPIC
CPU0:1
PCI_F/MODE
PCI1:5
48MHz/FS0
24MHz/FS1
SDRAM0
PLL1
PLL2
I
2
C
C
O
N
T
R
O
L
L
O
G
I
C
X2
X1
SDATA
SCLK
SDRAMIN
SDRAM12:13
SDRAM10/PCI_STOP#
SDRAM11/CPU_STOP#