ICS94211

www.DataSheet4U.com Integrated Circuit Systems, Inc. ICS94211 Programmable System Frequency Generator for PII/III™ Recommended Application: 440BX/VIA Apollo Pro133/ ALI 1631 style chipset. Output Features: 2 - CPUs @2.5V 1 - IOAPIC @ 2.5V 13 - SDRAM @ 3.3V 6 - PCI @3.3V, 1 - 48MHz, @3.3V 1 - 24MHz @ 3.3V 2 - REF @3.3V, 14.318MHz. Features: Programmable ouput frequency. Programmable ouput rise/fall time. Programmable PCICLK, PCICLK_F, SDRAM skew. Real time system reset output 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 Key Specifications: CPU – CPU: <175ps SDRAM - SDRAM: <500ps PCI – PCI: <500ps CPU(early)-PCI: Min=1.0ns, Typ=2.0ns, Max=4.0ns Pin Configuration VDDREF *PCI_STOP/REF0 GND X1 X2 VDDPCI *MODE/PCICLK_F **FS3/PCICLK0 GND PCICLK1 PCICLK2 PCICLK3 PCICLK4 VDDPCI BUFFER_IN GND SDRAM12 SDRAM11 VDDSDR SDRAM10 SDRAM9 GND SDATA SCLK 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 IOAPIC REF1/FS2* GND CPUCLK0 CPUCLK1 VDDLCPU RESET# SDRAM0 GND SDRAM1 SDRAM2 VDDSDR SDRAM3 SDRAM4 GND SDRAM5 SDRAM6 VDDSDR SDRAM7 SDRAM8 VDD48 48MHz/FS0* 24MHz/FS1* 48-Pin 300mil SSOP * Internal Pull-up Resistor of 120K to VDD ** Internal Pull-down resistor of 120K to GND Functi...