W83194BR-372
1. GENERAL DESCRIPTION
The W83194BR-372 is a Clock Synthesizer for SIS 746/748 chipset. W83194BR-372 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 ZCLK clock outputs; all clocks
are externally selectable with smooth transitions.
The W83194BR-372 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-372 accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V supply.
2. PRODUCT FEATURES
• 1 2.5V open drain Differential pairs clock outputs for CPU
• 1 2.5V open drain singled-ended clock output for chipset host bus.
• 2 3.3V ZCLK clock outputs
• 2 AGP clock outputs
• 8 PCI synchronous clocks
• 2 2.5V IOAPIC clock outputs
• 1 24_48Mhz clock output for super I/O.
• 1 48 MHz clock output for USB.
• 3 14.318MHz REF clock outputs.
• ZCLK/AGP/PCI clock out supports synchronous and asynchronous mode
• Smooth frequency switch with selections from 100 to 200MHz
• 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 Skew control
• 48-pin SSOP package
Publication Release Date: April 13, 2005
-1-
Revision 1.1