器件名称: W48S87-72
功能描述: Desktop/Notebook Frequency Generator
文件大小: 248.81KB 共19页
简 介:W48S87-72
Desktop/Notebook Frequency Generator
Features
Maximized EMI suppression using Cypress’s Spread Spectrum technology ±0.5% Spread Spectrum clocking Equivalent to the W48S67-72 with Spread Spectrum for Tilamook, MMO, and Deschutes processors Generates system clocks for CPU, IOAPIC, SDRAM, PCI, USB plus 14.318-MHz (REF0:1) Serial data interface (SDATA, SCLOCK inputs) provides additional CPU/PCI clock frequency selections, individual output clock disabling and other functions MODE input pin selects optional power management input control pins (reconfigures pins 26 and 27) Two fixed outputs separately selectable as 24-MHz or 48-MHz (default = 48-MHz) VDDQ3 = 3.3V±5%, VDDQ2 = 2.5V±5% Uses external 14.318-MHz crystal Available in 48-pin SSOP (300 mils) 10 CPU output impedance Table 1. Pin Selectable Frequency[1] 60/66_SEL 0 1 CPU, SDRAM Clocks (MHz) 60 66.8 PCI Clocks (MHz) 30 33.4
Block Diagram
VDDQ3 REF0 X1 X2 XTAL OSC PLL Ref Freq VDDQ2 IOAPIC VDDQ2 CPU0 CPU_STOP# I/O Control Stop Output Control CPU1 CPU2 CPU3 VDDQ3 SDRAM0 SDRAM1 SDRAM2 60/66_SEL PLL 1 SDRAM3 SDRAM4 SDRAM5 ÷2 SDRAM6 SDRAM7 PCI_F Stop Output Control Power Down Control PCI0 PCI1 PCI2 PWR_DWN# PCI3 PCI4 PCI5 PLL2 48/24MHZ 48/24MHZ REF1
Pin Configuration
REF1 REF0 GND X1 X2 MODE VDDQ3 PCI_F PCI0 GND PCI1 PCI2 PCI3 PCI4 VDDQ3 PCI5 GND 60/66_SEL SDATA SCLOCK VDDQ3 48/24MHZ 48/24MHZ GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 3……
