W83194BR-138 Datasheet | Winbond

DESCRIPTION The W83194BR-138 is a Clock Synthesizer for Intel 815 Solano chipset. W83194BR-138 provides all clocks required for high-speed RISC or CISC microprocessor and also provides 64 different frequencies of CPU, SDRAM, PCI, 3V66, IOAPIC clocks frequency setting. All clocks are externally selectable with smooth transitions. The W83194BR-138 provides I2C serial bus interface to program the registers to enable or disable each clock outputs and provides 0.25% and 0.5% center type spread spectrum to reduce EMI. The W83194BR-138 provides stepless frequency programming by controlling the VCO freq. and the clock output divisor ratio. Also the skew of CPU, SDRAM and 3V66 clock outputs are programmable. A watch dog timer is quipped and when time out, the RESET# pin will output 4ms pulse signal. The W83194BR-138 accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V supply. High drive PCI and SDRAM CLOCK outputs typically provide greater than 1 V /ns slew rate into 30 p F loads. CPU CLOCK outputs typically provide better than 1 V /ns slew rate into 20 p F loads as maintaining 50± 5% duty cycle. The fixed frequency outputs as REF, 24MHz, and 48 MHz provide better than 0.5V /ns slew rate. 2.0PRODUCT FEATURES - - - - - - - - - - - - - 2 CPU clocks 3 3V66 clocks 9 SDRAM clocks for 2 DIMMs 8 PCI synchronous clocks. Optional single or mixed supply: (VDDR = VDDP=VDDS = VDD48 = VDD3 = 3.3V, VDDA=VDDC=2.5V) Skew form CPU to PCI clock -1 to 4 ns, center 2.6 ns Smooth frequency switch with selections from 66.8 to 200MHz I2C 2-Wire serial interface and I2C read back 0.25% or 0.5% center type spread spectrum Programmable registers to enable/stop each output and select modes (mode as Tri-state or Normal ) 48 MHz for USB 24 MHz for super I/O Packaged in 48-pin SSOP -1- Publication Release Date: May 2000 Revision 0.37 PRELIMINARY 3.0 PIN CONFIGURATION REF1/- SEL24_48# VDDR Xin Xout VSS VSS 3V66-0 3V66-1 3V66-2 VDD3 VDDP PCICLK0/ FS0- PCICLK1/ FS1& VSS...