The ICS9178-03 generates all clocks required for high speed PowerPC RISC microprocessor systems. Generating clocks in phase with an external reference frequency allows the ICS9178-03 to be used as a multiplying zero delay buffer. Three different multiplying factors are externally selectable. These factors can be customized for specific applications. An external frequency can be directly applied to aid system testing. With 2X processor clock speeds up to 245 MHz, PECL outputs are provided. User selectable frequency ratios are available for PCLK/BCLK and PCLK/XCLK. Each pair of clocks outputs have separate supply pins to minimize output jitter and allow them to operate at 5V, 3.3V or custom voltage levels.