W83194AR-W Datasheet | Winbond

DESCRIPTION The W83194AR-W is a Clock Synthesizer for Intel Whitney chipset. W83194AR-W 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 W83194AR-W provides I2C serial bus interface to program the registers to enable or disable each clock outputs and provides 0.5% and 0.75% center type spread spectrum to reduce EMI. The W83194AR-W 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. 2.0 PRODUCT FEATURES - - - - - - - - - - - - 2 CPU clocks 9 SDRAM clocks for 2 DIMMs 8 PCI synchronous clocks. Optional single or mixed supply: (Vdd R = Vdd P=Vdd S = Vdd48 = Vdd3 = 3.3V, Vdd A=Vdd C=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 0.5% and 0.75% center type spread spectrum Programmable registers to enable/stop each output and select modes (mode as Tri-state or Normal ) Two 48 MHz pins for USB 24 MHz for super I/O 48-pin SSOP package -1- Publication Release Date: May. 1999 Revision 0.50 PRELIMINARY 3.0 PIN CONFIGURATION REFX2/- FS3 Vdd R Xin Xout Vss Vdd3 3V66-0 3V66-1 Vss3 PCICLK0/ - FS0 PCICLK1/ FS1# PCICLK2/- FS2 Vss P PCICLK3/FS4# PCICLK4 Vdd P PCICLK5 PCICLK6 PCICLK7 Vss48 48MHz_0 48MHz_1 - SIO_SEL/24_48MHz Vdd48 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 Vdd LAPIC IOAPIC Vdd LCPU CPUCLK0 CPUCLK1 Vss C Vdd S SDRAM 0 SDRAM 1 SDRAM 2 Vss...