W83194BR-903_06 Datasheet, PDF (5/26 Pages) Winbond – STEPLESS VIA PT/PM MAIN CLOCK GENERATOR

W83194BR-903/W83194BG-903
1. GENERAL DESCRIPTION
The W83194BR-903 is a Clock Synthesizer for VIA PT880/PM880 chipset. W83194BR-903 provides
all clocks required for high-speed microprocessor and provides step-less frequency programming and
32 different frequencies of CPU, PCI, and AGP clocks setting, support two 25MHz clock outputs, all
clocks are externally selectable with smooth transitions.
The W83194BR-903 provides I²C serial bus interface to program the registers to enable or disable
each clock outputs and provides -0.5% and +/-0.25% center type spread spectrum or programmable
S.S.T. scale to reduce EMI.
The W83194BR-903 also has watchdog timer and reset output pin to support auto-reset when
systems hanging caused by improper frequency setting.
The W83194BR-903 accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V supply.
2. PRODUCT FEATURES
• 3 0.7V current-mode Differential pairs clock outputs
• 2 2.5V 25MHz clock outputs
• 3 AGP clock outputs
• 10 PCI synchronous clocks
• 1 24_48Mhz clock output for super I/O.
• 1 48 MHz clock output for USB.
• 2 14.318MHz REF clock outputs.
• AGP/PCI clock out supports synchronous and asynchronous mode
• Smooth frequency switch with selections from 100 to 400MHz
• Step-less frequency programming
• I²C 2-Wire serial interface and support byte read/write and block read/write.
• -0.5% and +/- 0.25% center type spread spectrum
• Programmable S.S.T. scale to reduce EMI
• Programmable registers to enable/stop each output and select modes
• Programmable clock outputs Slew rate control and Skew control
• Watch Dog Timer and RESET# output pins
• 48-pin SSOP package
Publication Release Date: May 2006
-1-
Revision 1.0