ICS94211

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 Pin Configuration VDDREF 1 *PCI_STOP/REF0 2 GND 3 X1 4 X2 5 VDDPCI 6 *MODE/PCICLK_F 7 **FS3/PCICLK0 8 GND 9 PCICLK1 10 PCICLK2 11 PCICLK3 12 PCICLK4 13 VDDPCI 14 BUFFER_IN 15 GND 16 SDRAM12_F 17 SDRAM11 18 VDDSDR 19 SDRAM10 20 SDRAM9 21 GND 22 SDATA 23 SCLK 24 ICS94211 48 VDDLAPIC 47 IOAPIC 46 REF1/FS2* 45 GND 44 CPUCLK0 43 CPUCLK1 42 VDDLCPU 41 RESET# 40 SDRAM0 39 GND 38 SDRAM1 37 SDRAM2 36 VDDSDR 35 SDRAM3 34 SDRAM4 33 GND 32 SDRAM5 31 SDRAM6 30 VDDSDR 29 SDRAM7 28 SDRAM8 27 VDD48 26 48MHz/FS0* 25 24MHz/FS1* 48-Pin 300mil SSOP * Internal Pull-up Resistor of 120K to VDD ** Internal Pull-down resistor of 120K to GND Key Specifications: CPU – CPU: <175ps SDRAM ...