The W83194R-37/-58 is a Clock Synthesizer for VIA chipset. W83194R-37 provides all clocks required for high-speed RISC or CISC microprocessor such as Intel PentiumPro, AMD or Cyrix. Eight different frequencies of CPU, W83194R-58 provides all clocks required for high-speed RISC or CISC microprocessor such as Intel PentiumII and also provides 16 different frequencies of CPU clocks by software setting (additional register0 bit2). AGP and PCI clocks are externally selectable with smooth transitions. The W83194R-37/-58 provides AGP clocks especially for clone chipset, and makes SDRAM in synchronous frequency with CPU or AGP clocks. The W83194R-37/-58 provides I2C serial bus interface to program the registers to enable or disable each clock outputs and choose the 0.25%, 0.5% or 0.5%,1.5% center type spread spectrum to reduce EMI.