ICS9248-162 Datasheet | Integrated Circuit Systems

Integrated Circuit Systems, Inc. Frequency Generator & Integrated Buffers for PENTIUM/Pro TM & K6 General Description The ICS9248-162 is the single chip clock solution for various mobile chipset platforms. It provides all necessary clock signals for such a system. Spread spectrum may be enabled through I2C programming. Spread spectrum typically reduces system EMI by 8d B to 10d B. This simplifies EMI qualification without resorting to board design iterations or costly shielding. The ICS9248-162 employs a proprietary closed loop design, which tightly controls the percentage of spreading over process and temperature variations. Features • • • • Up to 137MHz frequency support Spread Spectrum for EMI control Serial I2C interface for Power Management, Frequency Select, Spread Spectrum. Provides the following system clocks - 4-CPUs @ 2.5/3.3V, up to 137MHz. (including CPUCLK_F) - 9-SDRAMs @3.3V, up to 137MHz (including SDRAM_F) - 8-PCI @3.3V, CPU/2 or CPU/3 (including 1 free running PCICLK_F) - 1-24/48MHz @3.3V - 1-48MHz @3.3V fixed - 2-REF @3.3V, 14.318MHz. Efficient Power management scheme through PCI and CLK STOP CLOCKS Spread Spectrum ± .25%, & 0 to -0.5% down spread • • Block Diagram PLL2 48MHz /2 X1 X2 BUFFER IN CPUCLK_F PLL1 Spread Spectrum FS(3:0) SEL24_48# STOP Pin Configuration VDDREF REF0 GNDREF X1 X2 VDDPCI - CPU2.5_3.3#/PCICLK_F - FS3/PCICLK0 GNDPCI - SEL24_48#/PCICLK1 PCICLK2 PCICLK3 PCICLK4 VDDPCI BUFFER IN GNDPCI PCICLK5 PCICLK6 VDDCOR PCI_STOP# - PD# GND48 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 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 REF1/FS2- VDDLCPU CPUCLK_F CPUCLK0 GNDLCPU CPUCLK1 CPUCLK2 CLK_STOP# GNDSDR SDRAM_F SDRAM0 SDRAM1 VDDSDR SDRAM2 SDRAM3 GNDSDR SDRAM4 SDRAM5 VDDSDR SDRAM6 SDRAM7 VDD48 48MHz/FS0- 24_48MHz/FS1- 24_48MHz XTAL OSC REF(1:0) CPUCLK (2:0) LATCH STOP SDRAM (7:0) SDRAM_F CLK_STOP# PCI_STOP# CPU2.5_3.3# SDATA SCLK PD# Control Logic...