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Integrated Circuit Systems, Inc.
ICS951413
Programmable System Clock Chip for ATI RS400 P4TM-based Systems
Recommended Application: ATI RS400 systems using Intel P4TM processors Output Features: • 6 - Pairs of SRC/PCI Express* clocks • 2 - Pairs of programmable SRC/PCI Express (ATIG) clocks • 3 - Pairs of Intel P4 clocks • 3 - 14.318 MHz REF clocks • 1 - 48MHz USB clock • 1 - 33 MHz PCI clock seed Key Specifications: • CPU outputs cycle-cycle jitter < 85ps • SRC output cycle-cycle jitter <125ps • PCI outputs cycle-cycle jitter < 250ps • +/- 300ppm frequency accuracy on CPU & SRC clocks Features/Benefits: • 2 - Programmable Clock Request pins for SRC clocks • Supports CK410 or CK409 frequency table mapping • Spread Spectrum for EMI reduction • Outputs may be disabled via SMBus • External crystal load capacitors for maximum frequency accuracy
Functionality - (CK410# = 0) SRC PCI 1 1 1 CPU FS_C FS_B FS_A MHz MHz MHz 0 266.66 100.00 33.33 0 1 133.33 100.00 33.33 0 0 200.00 100.00 33.33 1 1 166.66 100.00 33.33 0 333.33 100.00 33.33 0 1 100.00 100.00 33.33 1 0 400.00 100.00 33.33 1 1 RESERVED Functionality - (CK410# = 1) FS_C 1 1 CPU Byte6 FS_B FS_A MHz bit5 0 1 0 1 0 1 0 1 0 0 1 1 0 0 1 1 100.00 200.00 133.33 166.67 200.00 400.00 266.67 333.33
1
Pin Configuration
REF MHz 14.318 14.318 14.318 14.318 14.318 14.318 14.318 14.318 USB MHz 48.000 48.000 48.000 48.000 48.000 48.000 48.000 48.000
0
1
100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00
33.33 33.33 33.33 33.33 33.33 33.33 33.33 33.33
14.318 14.318 14.318 14.318 14.318 14.318 14.318 14.318
48.000 48.000 48.000 48.000 48.000 48.000 48.000 48.000
1. FS_C, FS_B and FS_A are low-threshold inputs. Please see the V IL_FS and VIH_FS specifications in the Input/Supply/Common Output Parameters Table for correct values.
Note: Pins preceeded by '**' have a 120 Kohm Internal Pull Down resistor Pins preceeded by '*' have a 120 Kohm Internal Pull Up resistor
56-pin SSOP & TSSOP
0929C—03/07/05
*Other names and brands may be claimed as the property of others.
ICS951413
SRC MHz
PCI MHz
REF MHz
USB MHz
X1 X2 VDD48 USB_48MHz GND VTT_PWRGD#/PD SCLK SDATA **FS_C **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 **FS_A/REF0 **FS_B/REF1 **TEST_SEL/REF2 VDDPCI **CK410#/PCICLK0 GNDPCI *CPU_STOP# CPUCLKT0 CPUCLKC0 VDDCPU GNDCPU CPUCLKT1 CPUCLKC1 CPUCLKT2_ITP CPUCLKC2_ITP VDDA GNDA IREF GNDSRC VDDSRC SRCCLKT0 SRCCLKC0 VDDATI GNDATI ATIGCLKT0 ATIGCLKC0
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Integrated Circuit Systems, Inc.
ICS951413
Pin Description
PIN # 1 2 3 4 5 6 7 8 9 PIN NAME X1 X2 VDD48 USB_48MHz GND VTT_PWRGD#/PD SCLK SDATA **FS_C PIN TYPE IN OUT PWR OUT PWR IN IN I/O IN DESCRIPTION Crystal input, Nomi.