[AMI]

Description

The FS6261-01 is a CMOS clock generator IC designed for high-speed motherboard applications. Two different frequencies can be selected for the CPU clocks via two SEL pins. Glitch-free stop clock control of the CPU, AGP (66MHz) and PCI clocks is provided. A low current power-down mode is available for mobile applications. Separate clock buffers provide for a 2.5V voltage range on the CPU_0:3, CPU/2_0:1 and APIC_0:2 clocks.

Features

• Generates clocks required for Intel® i820 based desktop and workstation systems, including:

♦ Four enabled 2.5V 133/100MHz CPU Front Side Bus (FSB) clocks

♦ Two 2.5V CPU/2 clocks for synchronous memory

♦ Seven enabled 3.3V PCI bus clocks and one free-running PCI clock

♦ Four enabled 3.3V 66MHz AGP clocks

♦ Three 2.5V 16.67MHz APIC bus clocks

♦ Two 3.3V 14.318MHz REF clocks

♦ One 3.3V 48MHz USB clock

• CPU clock cycle – cycle jitter < 150ps p-p

• Non-linear spread-spectrum modulation (-0.5 at 31.5kHz)

• Supports test mode and tristate output control

• Separate CPU-enable, PCI-enable and power-down inputs with glitch-free stop clock controls on all clocks for clock control and power management