The MK1493-03B is a general purpose clock generator device that provides an integrated clocking solution for PCI /networking applications. It provides eight individually programmable PCI clocks, one CPU clock, three additional fixed PCI clocks, and a 25 MHz reference clock for LAN support. This part incorporates IDT's newest clock technology, offering more robust features and functionality. The device provides a gradual transition from its initial clock frequency to the new one. Using a serially programmable SMBus interface, the MK1493-03B can select the output clock frequency and the transition from the original value to the new value. The SMBus also allows each of the 8 programmable PCI clocks to be individually enabled and disabled.