The CY2254A is a Clock Synthesizer/Driver that provides the multiple clocks required for a Pentium-based PC. The CY2254A has low-skew outputs (< 250 ps between the CPU Clocks, < 250 ps between the PCI Clocks). In addition, the CY2254A CPU clock outputs have less than 200 ps cycle- to-cycle jitter. Finally, both the PCI and CPU clock outputs meet the 1 V/ns slew rate requirement of a Pentium processor- based system. The CY2254A accepts a 14.318 MHz reference signal as its input. The CY2254A has 2 PLLs, one of which generates the CPU and PCI clocks, and the other generates the I/O and Keyboard Controller or USB clocks. The CY2254A runs off either a 3.3V or 5V supply. The CY2254A is available in two options. The −1 option supports the Intel Triton PCIset and provides a 12 MHz keyboard clock on pin 25. The −2 option provides a 48 MHz USB clock on pin 25 and supports the Cyrix® M1 processor.