ICS951412

www.DataSheet4U.com Integrated Circuit Systems, Inc. ICS951412 System Clock Chip for ATI RS480 K8-based Systems Recommended Application: ATI RS480 systems using AMD K8 processors Output Features: 3 - 14.318 MHz REF clocks 1 - USB_48MHz USB clock 1 - HyperTransport 66 MHz clock seed 1 - PCI 33 MHz clock seed 2 - Pairs of AMD K8 clocks 6 - Pairs of SRC/PCI Express* clocks 2 - Pairs of ATIG (SRC/PCI Express) clocks Features: 2 - Programmable Clock Request pins for SRC clocks Spread Spectrum for EMI reduction Outputs may be disabled via SMBus External crystal load capacitors for maximum frequency accuracy Pin Configuration X1 X2 VDD48 USB_48MHz GND NC SCLK SDATA **FS2 **CLKREQA# **CLKREQB# SRCCLKT7 SRCCLKC7 VDDSRC GNDSRC SRCCLKT6 SRCCLKC6 SRCCLKT5 SRCCLKC5 GNDSRC VDDSRC SRCCLKT4 SRCCLKC4 SRCCLKT3 SRCCLKC3 GNDSRC ATIGCLKT1 ATIGCLKC1 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 VDDREF GND **FS0/REF0 **FS1/REF1 REF2 VDDPCI PCICLK0 GNDPCI VDDHTT HTTCLK0 GNDHTT CPUCLK8T0 CPUCLK8C0 VDDCPU GNDCPU CPUCLK8T1 CPUCLK8C1 VDDA GNDA IREF GNDSRC VDDSRC SRCCLKT0 SRCCLKC0 VDDATI GNDATI ATIGCLKT0 ATIGCLKC0 Note: Pins preceeded by '**' have a 120 Kohm Internal Pull Down resistor 56 Pin SSOP/TSSOP Power Groups Pin Number VDD 56 51 48 43 14, 21, 32,35 39 3 GND 55 49 46 42 15, 20, 26,31,36 38 5 Description Xtal, REF PCICLK output HTTCLK output CPU Outputs SRC o...