System Clock Chip - ICS
Description
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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 outputs Analog, CPU PLL USB_48MHz output
Functionality
FS2 0 0 0 0 1 1 1 FS1 0 0 1 1 0 0 1 FS0 0 1 0 1 0 1 1 CPU MHz Hi-Z X 180.
00 220.
00 100.
00 133.
33 200.
00 HTT MHz Hi-Z X/3 60.
00 73.
12 66.
66 66.
66 66.
66 PCI MHz Hi-Z X/6 30.
00 36.
56 33.
33 33.
33 33.
33
0883G—12/08/04
*Other names and brands may be claimed as the property of others.
ICS951412
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ICS951412
Pin Descriptions
PIN # 1 2 3 4 5 6 7 8 9 10 PIN NAME X1 X2 VDD48 USB_48MHz GND NC SCLK SDATA **FS2 **CLKREQA# PIN TYPE I...
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