W83194R-KX Datasheet, PDF (1/13 Pages) Winbond – 133MHZ 3-DIMM K7 CLOCK

W83194R-KX
133MHZ 3-DIMM K7 CLOCK
1.0 GENERAL DESCRIPTION
The W83194R-KX is a clock generator which provides all clocks required for AMD K7 system.
W83194R-KX provides one differential pair CPU clock open drain outputs up to 143MHz which are
externally selectable with smooth transitions. W83194R-KX also provides 6 PCI clocks and 13
SDRAM clocks controlled by the none-delay buffer_in pin.
The W83194R-KX accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V supply.
Spread spectrum built in at ±0.5% or ±0.25% to reduce EMI. Programmable stopping individual clock
outputs and frequency selection through I²C interface. The device meets the Pentium power-up
stabilization, which requires CPU and PCI clocks be stable within 2 ms after power-up.
High drive six PCI and thirteen SDRAM CLOCK outputs typically provide greater than 1 V /ns slew
rate into 30 pF loads. Two CPU CLOCK outputs typically provide better than 1 V /ns slew rate into 20
pF loads, when maintaining 50± 5% duty cycle. The fixed frequency outputs, such as REF, 24MHz,
and 48 MHz provide better than 0.5V /ns slew rate.
2.0 PRODUCT FEATURES
• Supports AMD K7 CPU with I²C.
• One pair of differential CPU clocks
• One chipset clock
• 13 SDRAM clocks for 3 DIMMs
• 6 PCI synchronous clocks
• Optional single or mixed supply:
(Vddq3=Vddq2 =3.3V) or (Vddq3 = 3.3V, Vddq2 = 2.5V)
• < 250ps skew among CPU clocks
• < 250ps skew among PCI clocks
• < 5ns propagation delay SDRAM from buffer input
• Skew from CPU(earlier) to PCI clock 1.5 to 4ns, center 2.6ns.
• Smooth frequency switch with selections from 66.8 MHz to 143 MHz CPU
• I²C 2-Wire serial interface and I²C read back
• ± 0.25% or ± 0.5% spread spectrum function to reduce EMI
• Programmable registers to enable/stop each output and select modes
(mode as Tri-state or Normal )
• One 48 MHz for USB & one 24 MHz for super I/O
• 48-pin SSOP package
Publication Release Date: Nov. 1999
-1-
Revision 0.35