ICS9148-93

Integrated Circuit Systems, Inc. ICS9148-93 Advance Information Frequency Generator & Integrated Buffers for PENTIUM/ProTM General Description The ICS9148-93 is the single chip clock solution for Desktop/ Notebook designs using the VIA MVP3 style chipset. 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 8dB to 10dB. This simplifies EMI qualification without resorting to board design iterations or costly shielding. The ICS9148-93 employs a proprietary closed loop design, which tightly controls the percentage of spreading over process and temperature variations. Serial programming I C interface allows changing functions, stop clock programming and frequency selection. The SD_SEL latched input allows the SDRAM frequency to follow the CPUCLK frequency(SD_SEL=1) or the AGP clock frequency(SD_SEL=0). 2 Features • Generates the following system clocks: - 4 CPU(2.5V/3.3V) upto 100MHz. - 6 PCI(3.3V) @ 33.3MHz - 2AGP(3.3V) @ 2 x PCI - 12 SDRAMs(3.3V) @ either CPU or AGP - 2 REF (3.3V) @ 14.318MHz Skew characteristics: - CPU – CPU<250ps - SDRAM – SDRAM < 250ps - CPU – SDRAM < 250ps - CPU(early) – PCI : 1-4ns Supports Spread Spectrum modulation +0.25, ±0.6% Serial I2C interface for Power Management, Frequency Select, Spread Spectrum. Efficient Power management scheme through PCI and CPU STOP CLOCKS. Uses external 14.318MHz crystal 48 pin 300mil SSOP. • • • • • • Block D...