W83194AR-73 Datasheet | Winbond

DESCRIPTION The W83194AR-73 is a Clock Synthesizer for Intel Whitney chipset. W83194AR-73 provides all clocks required for high-speed RISC or CISC microprocessor and also provides 32 different frequencies of CPU, SDRAM, PCI, 3V66, IOAPIC clocks frequency setting. All clocks are externally selectable with smooth transitions. The W83194AR-73 provides I2C serial bus interface to program the registers to enable or disable each clock outputs and provides 0.25% center and 0-0.5% down type spread spectrum to reduce EMI. The W83194AR-73 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¡Ó 5% duty cycle. The fixed frequency outputs as REF, 24MHz, and 48 MHz provide better than 0.5V /ns slew rate. 1.0 PRODUCT FEATURES - - - - - - - - - - - - 2 CPU 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 150MHz I2C 2-Wire serial interface and I2C read back 0.25% center and 0-0.5% down 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 1999 Revision 0.40 PRELIMINARY 3.0 PIN CONFIGURATION REF1/- SEL_3V66 VDDR Xin Xout VSS VSS 3V66-0 3V66-1 VDD3 VDDP PCICLK0/ - FS0 PCICLK1/ - FS1 PCICLK2/- SEL24_48# VSS PCICLK3 PCICLK4 PCICLK5 VDDP PCICLK6 PCICLK7 VSS PD# - SDCLK - SDATA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Vdd A IOAPIC VDDC CPUCLK0 CPUCLK1 VSS VSS SDRAM 0 SDRAM 1 SDRAM 2 VDDS SDRAM 3 SDRAM 4 SDRAM 5 VSS SDRAM 6 SDRAM 7 SDRAM_F VDDS VSS 24_48MHz/ - FS2 48MHz-0...