W83193R-02 Datasheet, PDF (1/18 Pages) Winbond – 83.3 MHZ 3-DIMM CLOCK

Preliminary W83193R-02/-04/-04A
83.3 MHZ 3-DIMM CLOCK
1.0 GENERAL DESCRIPTION
The W83193R-02/-04/-04A is a Main board Clock Synthesizer which provides all clocks required for
high-speed RISC or CISC microprocessor such as Intel PentiumPro, PentiumII, AMD or Cyrix. Eight
different frequency of CPU and PCI clocks are externally selectable with smooth transitions.
The W83193R-02/-04/-04A also provides I2C serial bus interface to program the registers to enable
or disable each clock outputs and choose the 0.5% or 1.5% center type spread spectrum.
The W83193R-02/-04/-04A accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V
supply. High drive PCI and SDRAM CLOCK outputs typically provide greater than 1V /nS slew rate
into 30 pF loads. CPU CLOCK outputs typically provide better than 1V /nS slew rate into 20 pF loads
as maintaining 50 ±5% duty cycle. The fixed frequency outputs as REF, 24 MHz, and 48 MHz provide
better than 0.5V /nS slew rate.
2.0 FEATURES
• Supports Pentium™, Pentium™ Pro, Pentium™ II, AMD and Cyrix CPUs with I²C.
• 4 CPU clocks
• 12 SDRAM clocks for 3 DIMs.
• 7 PCI synchronous clocks.
• One IOAPIC clock for multiprocessor support.
• Optional single or mixed supply:
(VDD = VDDq3 = VDDq2 = VDDq2b = 3.3V) or (VDD = VDDq3 = 3.3V, VDDq2 = VDD2b = 2.5V)
• < 250 pS skew among CPU and SDRAM clocks.
• < 250 pS skew among PCI clocks.
• Smooth frequency switch with selections from 50 MHz to 83.3 MHz CPU. (W83193R-04)
• Smooth frequency switch with selections from 50 MHz to 112 MHz CPU. (W83193R-04A)
• I²C 2-Wire serial interface and I²C read back.
• Spread spectrum function to reduce EMI.
• Programmable registers to enable/stop each output and select modes
(mode as Tri-state or Normal)
• MODE pin for power Management
• 48 MHz for USB
• 24 MHz for super I/O
• Packaged in 48-pin SSOP
Publication Release Date: April 1999
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Revision A1