ICS951901

www.DataSheet4U.com Integrated Circuit Systems, Inc. ICS951901 Programmable Frequency Generator & Integrated Buffers for Pentium III Processor Recommended Application: Single chip clock solution for IA platform. Output Features: 3 - CPU @ 2.5V 13 - SDRAM @ 3.3V 6 - PCI @3.3V, 2 - AGP @ 3.3V 1 - 48MHz, @3.3V fixed. 1 - 24/48MHz, @3.3V selectable by I2C (Default is 24MHz) 2 - REF @3.3V, 14.318MHz. Features: Programmable ouput frequency. Programmable ouput rise/fall time. Programmable SDRAM and CPU skew. Spread spectrum for EMI control typically by 7dB to 8dB, with programmable spread percentage. Watchdog timer technology to reset system if over-clocking causes malfunction. Uses external 14.318MHz crystal. FS pins for frequency select Skew Specifications: CPU - CPU: < 175ps SDRAM - SDRAM < 250ps (except SDRAM12) PCI - PCI: < 500ps CPU (early) - PCI: 1-4ns (typ. 2ns) Pin Configuration VDDA *(AGPSEL)REF0 1 *(FS3)REF1 GND X1 X2 VDDPCI *(FS1)PCICLK_F *(FS2)PCICLK0 PCICLK1 PCICLK2 PCICLK3 PCICLK4 GND VDDAGP AGPCLK0 AGPCLK1 GND GND *(FS0)48MHz *(MODE)24_48MHz VDD48 SDATA SCLK 1 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 32 31 30 29 28 27 26 25 VDDL CPUCLK0 CPUCLK1 CPUCLK2 GND VDDSDR SDRAM0 SDRAM1 SDRAM2 GND SDRAM3 SDRAM4 SDRAM5 VDDSDR SDRAM6 SDRAM7 GND SDRAM8/PD# SDRAM9/SDRAM_STOP# GND SDRAM10/PCI_STOP# SDRAM11/CPU_STOP# SDRAM12 VDDSDR 48-Pin 300mil SSOP * These inputs have ...