GENERAL DESCRIPTION

The W83194BR-63S is a Clock Synthesizer which provides all clocks required for high-speed RISC or CISC microprocessor such as Intel Pentium II or Pentium III. W83194BR-63S provides 64 CPU/PCI frequencies which are selectable with smooth transitions by hardware or software. W83194BR-63S also provides 13 SDRAM clocks.

The W83194BR-63S provides step-less frequency programming by controlling the VCO freq. and the programmable PCI clock output divisor ratio. A watch dog timer is quipped and when time out, the RESET# pin will output 4ms pulse signal.

The W83194BR-63S accepts a 14.318 MHz reference crystal as its input. Spread spectrum built in at 0~-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. Using dual function pin for the slots(ISA, PCI, CPU, DIMM) is not recommend.

PRODUCT FEATURES

• Supports Pentium II and Pentium III CPU with I2C.

• 3 CPU clocks (one free-running CPU clock)

• 13 SDRAM clocks for 3 DIMMs

• 6 PCI synchronous clocks

• 2 AGP clocks

• 2 REF clocks as 14.318MHz outputs

• < 250ps skew among CPU and SDRAM clocks

• < 250ps skew among PCI clocks

• Skew from CPU(earlier) to PCI clock 1 to 4ns, center 2.6ns.

• Smooth frequency switch with selections from 66 MHz to 200 MHz CPU

• Stepless frequency programming by controlling the VCO freq. and the clock output divisor ratio

• Programmable skew for CPU to SDRAM and CPU to AGP clock outputs

• I2C 2-Wire serial interface and I2C read back

• 0~-0.25 or ±0.5 spread spectrum function to reduce EMI

• Programmable registers to enable/stop each output and select modes

• MODE pin for power Management and RESET# out when system hang

• One 48 MHz for USB & one 24_48 MHz for super I/O

• 48-pin SSOP package