OVERVIEW

The SM8702AM is a clock generator IC that can generate clock signals up to and exceeding 100MHz for personal computer (PC) motherboards. It uses a single 14.318MHz crystal oscillator element and 2 built-in PLLs to simultaneously and independently generate 2 CPU clocks, 6 PCI bus clocks, 2 reference clocks with the same frequency as the crystal element, 48MHz USB interface clock, and 24MHz Super I/O chip clock outputs. It also has 14 outputs that can function as SDRAM clocks by buffering an external input SDRAM clock.

FEATURES

■ Intel® Pentium® II, Pentium® III, and AMD x86- compatibles supported

■ 2.5/3.3V CPU clock outputs and IOAPIC clock output

■ 14 × SDRAM clock outputs (3 DIMMs)

■ 2 × CPU clock outputs (60), 66, 75, 83, 95, 100, 103, 112, (124), 133MHz CPU/SDRAM clock frequencies. Values in parentheses are available as mask options.

■ 6 × PCI bus clock outputs (one free-running output) 33MHz or 1/2, 1/3, 1/4 of the CPU clock frequency

■ 2 × reference clock outputs and 1 × IOAPIC clock output 14.318MHz REF/IOAPIC clock frequency

■ 1 × 48MHz USB interface clock output

■ 1 × 24MHz clock output for Super I/O chip

■ I2C serial data bus for frequency/mode output control

■ CPU-stop and PCI-stop functions

■ Spread Spectrum Clock Generator (SSCG) outputs Center spread/Down spread, ± 0.5 or ± 1.5

■ 3.3V (VDD) and 2.5/3.3V (VDDL) supply voltages

■ 48-pin SSOP package (pin compatible with ICS9148-26)

APPLICATIONS

■ PC motherboards using Intel® Pentium®, Pentium® II/III, AMD-K6 devices, and x86 architecture CPUs