The ICS9147-14 generates all clocks required for high speed RISC or CISC microprocessor systems such as Intel PentiumPro. Two bidirectional I/O pins (FS1,FS2) are latched at power-on to the functionality table, with FS0 selectable in real-time to toggle between conditions. High drive PCICLK and SDRAM outputs typically provide greater than 1 V/ns slew rate into 30 pF loads. CPU outputs typically provide better than 1V/ns slew rate into 20 pF loads while maintaining 5 0 5% duty cycle. The REF clock outputs typically provide better than 0.5V/ns slew rates. Seperate buffers supply pins VDDL1 allow for 3.3V or reduced voltage swing (from 2.9 to 2.5V) for CPU (0:3) and IOAPIC outputs.