ICS94222

Integrated Circuit Systems, Inc. ICS94222 Advance Information Programmable System Frequency Generator for PII/III™ Recommended Application: BX, Appollo Pro 133 type of chip set. Output Features: 3 - CPUs @2.5V, up to 166MHz. 17 - SDRAM @ 3.3V, up to 166MHz. 7 - PCI @3.3V 2 - IOAPIC @ 2.5V 1 - 48MHz, @3.3V fixed. 1 - 24MHz @ 3.3V 2 - REF @3.3V, 14.318MHz. Features: Programmable ouput frequency. Programmable ouput rise/fall time. Programmable PCI_F and PCICLK 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 Key Specifications: CPU – CPU: <175ps SDRAM - SDRAM: <500ps PCI – PCI: <500ps CPU-SDRAM: <500ps CPU(early)-PCI: Min=1.0ns, Typ=2.0ns, Max=4.0ns Pin Configuration AVDD *FS2/REF1 *PCI_STOP#/REF0 GND X1 X2 VDD *MODE/PCICLK_F *FS3/PCICLK0 GND PCICLK1 PCICLK2 PCICLK3 PCICLK4 VDD PCICLK5 BUFFERIN SDRAM11 SDRAM10 VDD SDRAM9 SDRAM8 GND SDRAM15 SDRAM14 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 25 26 27 28 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 VDDL IOAPIC0 IOAPIC_F GND CPUCLK_F CPUCLK0 VDDL CPUCLK1 GND CLK_STOP* SDRAM_F VDDSDR SDRAM0 SDRAM1 GND SDRAM2 SDRAM3 SDRAM4 SDRAM5 VDD SDRAM6 SDRAM7 GND SDRAM12 SDRAM13 AVDD48 24MHz/FS0* 1 48MHz/FSI* 56-Pin SSOP * Internal Pull-up Resi...