W48S87-04

Preliminary Information W48S87-04 Spread Spectrum 3 DIMM Desktop Clock Features Outputs - 4 CPU Clock (2.5V or 3.3V, 50 to 83.3MHz) - 7 PCI (3.3V) - 1 48MHz for USB (3.3V) - 1 24MHz for Super I/O (3.3V) - 2 REF (3.3V) - 1 IOAPIC (2.5V or 3.3V) - 12 SDRAM Serial data interface provides additional frequency selection, individual clock output disable, and other functions Smooth transition supports dynamic frequency assignment Frequency selection not affected during power down/up cycle Supports a variety of power saving options 3.3V operation Available in 48-pin SSOP (300 mils) Key Specifications ±0.5% Spread Spectrum Modulation: ±0.5% Jitter (cycle-to-cycle): 250ps Duty Cycle: 45-55% 1-4ns CPU-PCI skew 250ps PCI-PCI or CPU-CPU skew Figure 1 Block Diagram SDATA SCLOCK X1 X2 CPU3.3#_2.5 FS0 FS1 FS2 CPU_STOP# PWR_DWN# Serial Port XTAL OSC Device Control PLL Ref Freq VDD1 CPU Clock Mode Control Freq Select I/O MODE REF0/CPU3.3#_2.5 REF1(CPU_STOP#...