W83194BR-648

The W83194BR-648 is a Clock Synthesizer for SIS P4 series chipset. W83194BR-648 provides all clocks required for high-speed Intel Pentium 4, and also provides 32 different frequencies of CPU clocks frequency setting. All clocks are externally selectable with smooth transitions. The W83194BR- 648 makes SDRAM in synchronous or asynchronous frequency with CPU clocks.

The W83194BR-648 provides step-less frequency programming by controlling the VCO freq. and the programmable AGP, PCI clock output divisor ratio. AGP and PCI frequency can be fixed to be four kinds of different frequency outputs. A watchdog timer is quipped and when time out, register9 bit5 will be set to 1 for warning. 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 W83194BR-648 accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V supply. High drive PCI CLOCK outputs typically provide greater than 1V /nS slew rate into 30 pF loads. The fixed frequency outputs as REF, 24 MHz, and 48 MHz provide better than 0.5V /nS slew rate.