General Description

The ICS9159-07 is a low-cost frequency generator designed specifically for NexGen Nx586 systems. The integrated buffer minimizes skew and provides the CPU clocks required by the NexGen Nx586 microprocessor. A 14.318 MHz XTAL oscil-lator provides the reference clock to generate standard Nx586 frequencies. The CPU clock makes gradual frequency transi-tions without violating the PLL timing of internal microproc-essor clock multipliers.

Either synchronous (2XCPU/3) or asynchronous (32 MHz) PCI bus operation can be selected. Green PC systems are supported through doze mode.

Features

• Three CPU clocks operate up to 65 MHz at 3.3V, plus smooth transitions

• Selection of nine frequencies, tristate

• Seven BUS clocks support sync or async bus operation

• Integrated buffer outputs drive up to 10pF loads

• 3.13 to 5.25V (3.3±5, 5.0±5) supply range

• 28-pin SOIC package

• Clock duty cycles 45/55

Applications

• Ideal for NexGen Nx586 PCI-based motherboard designs