器件名称: W48C101-01
功能描述: Spread Spectrum BX System Frequency Generator
文件大小: 112.52KB 共8页
简 介:PRELIMINARY
W48C101-01
Spread Spectrum BX System Frequency Generator
Features
Maximized EMI suppression using Cypress’s Spread Spectrum technology Four copies of CPU output Eight copies of PCI output (Synchronous w/CPU output) Two copies of 14.318-MHz IOAPIC output Two copies of 48-MHz USB output Three buffered copies of 14.318-MHz reference input Input is a 14.318-MHz XTAL or reference signal Selectable 100-MHz or 66-MHz CPU outputs Power management control input pins Test mode and output three-state capability CPU0:3 Clock Skew: ...................................................175 ps PCI_F, PCI1:7 Clock Skew: ......................................... 500 ps CPU to PCI Clock Skew: .............. 1.5 to 4.0 ns (CPU Leads) Logic inputs have 250-k pull-up resistors except SEL100/66#. Table 1. Pin Selectable Frequency SEL 100/66# 0 0 0 0 1 1 1 1 SEL1 0 0 1 1 0 0 1 1 SEL0 0 1 0 1 0 1 0 1 CPU PCI (MHz) (MHz) HI-Z 66.6 66.6 66.6 X1/2 100 100 100 HI-Z 33.3 33.3 33.3 X1/6 33.3 33.3 33.3 SPREAD#=0 Don’t Care ±0.9% Center –1% Down –0.5% Down Don’t Care ±0.9% Center –1% Down –0.5% Down
Key Specifications
Supply Voltages: ....................................... VDDQ3 = 3.3V±5% VDDQ2 = 2.5V±5% CPU0:3 Jitter (Cycle to Cycle): ................................... 200 ps
Block Diagram
VDDQ3 REF0 X1 X2 XTAL OSC PLL Ref Freq VDDQ2 APIC0 APIC1 VDDQ2 CPU_STOP# Stop Clock Control SEL100/66# SEL0 SEL1 SPREAD# PLL 1 ÷2/÷3 VDDQ3 PCI_F Stop Clock Control PCI_STOP# PCI1 PCI2 PCI3 CPU0 C……
