PI6C671F

The PI6C671F is a mixed-voltage clock generator designed to provide all timing signals for Intel Pentium/Pentium II module-based motherboards. PI6C671F provides four CPU, seven PCI, and up to eight SDRAM clocks. Additionally, three reference clocks (same frequency as the crystal) and two selectable 24/48 MHz clocks are available.

Pericom design improvements resulted in a low-power device optimized for 2.5V CPU operation. A special spread-spectrum feature may be enabled to minimize EMI.

The two-wire I2C serial interface of PI6C671F can be used to reduce circuit noise and power consumption. I2C control lets you enable/disable each clock output driver, change CPU frequencies, and select 24 or 48 MHz outputs.

A power-down function of PI6C671F (pin 44) puts the whole system in a lowpower mode by stopping the crystal oscillator and both PLLs. CPU and PCI clocks may also be stopped by the "CPU_STOP#" (pin 27), and "PCI _STOP#" (pin 26) functions.