VT8225

VIA Technologies, Inc. 1045 Mission Court. Fremont, CA 94539 USA TEL: 1-510-683-3300 FAX: 1-510-683-3301 VT8225 8th. Fl., No. 533 Chung-cheng Rd.,Hsin-tien Taipei, Taiwan, R.O.C. TEL: 886-2-218-5452 FAX: 886-2-218-5453 VT8225 Clock Generator Date: July 5, 1994 Features ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ Generates essential clock signals for the motherboard 4V to 7V operating supply range Supports 80286, 80386 and 80486 based designs Wide range of selectable output frequencies < 2ns skew between CPU and 2X CPU clock outputs Single low cost crystal (14.318Mhz) used as reference frequency Smooth transition on frequency switching 50% duty cycle Power down mode for low power consumption TTL or CMOS compatible outputs with 12mA drive capability Low, short and long term jitter 14 pin DIP and 14 pin SOIC (300 mil body) package options Description The VT8225 is a universal clock generator for motherboard design. The product at a glimpse: 1. Generates all kinds of required clocks for CPU and bus operation from 6 Mhz to 80 Mhz. 2. Eliminates at least two oscillators, which are oscillators for CPU and 14.318MHz oscillator. 3. Simplifies inventory: VT8225 covers required main clock for the motherboard design. 4. Provides a reliable clock for the PLL design. 5. Is pin-to-pin compatible to oscillator. -1- VIA Technologies, Inc. VT8225 VT8225 Signal Description Symbol Pin No. X1 X2 S0 S1 S2 S3 MCLK RESET# TS OSC 2 3 4 5 10 9 8 11 1 13 Type I I/O I I I I O O I O Functions These pins form an o...