ICS9147-03

Integrated Circuit Systems, Inc. ICS9147-03 Frequency Generator & Integrated Buffers for 686 Series CPUs General Description The ICS9147-03 generates all clocks required for high speed RISC or CISC microprocessor systems such as Intel PentiumPro, AMD or Cyrix processors. Four bidirectional I/O pins (FS0, FS1, FS2, BSEL) are latched at power-on to the functionality table. The Six BUS clocks can be selected as either synchronous at 1/2 CPU speed or asynchronous at 32MHz selected by BSEL latched input.The inputs provide for tristate and test mode conditions to aid in system level testing.These multiplying factors can be customized for specific applications. Glitch-free stop clock controls provided for SDRAM(5:8) and SDRAM (9:12) banks (STP2#, STP3#). High drive BUS 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 20pF loads while maintaining 50±5% duty cycle. The REF clock outputs typically provide better than 0.5V/ns slew rates. Seperate buffer supply pin VDDL allows for nominal 3.3V voltage or reduced voltage swing (from 2.9 to 2.5V) for CPUL (1:2) and IOAPIC outputs. Features Total of 15 CPU speed clocks: - Two copies of CPU clock with VDDL (2.5 to 3.3V) - Twelve (12) SDRAM (3.3v) plus one CPUH/AGP (3.3V) clocks Six copies of BUS clocks (synchronous with CPU clock/2 or asynchronous 32 MHz) 250ps output skew window for CPU andSDRAM clocks and 500ps window BUS clocks. CPU cloc...