W83194BR-39B中文资料华邦电子数据手册PDF规格书

GENERAL DESCRIPTION

The W83194BR-39B is a Clock Synthesizer which provides all clocks required for high-speed RISC or CISC microprocessor such as Intel Pentium II or Pentium III. W83194BR-39B provides 64 CPU/PCI frequencies which are selectable with smooth transitions by hardware or software. W83194BR-39B also provides 13 SDRAM clocks controlled by the none-delay buffer_in pin.

PRODUCT FEATURES

• Supports PentiumÔ II and !!! CPU with I2C.

• 2 CPU clocks (one free-running CPU clock)

• 13 SDRAM clocks for 3 DIMMs

• 6 PCI synchronous clocks

• One IOAPIC clock for multiprocessor support

• Optional single or mixed supply:

(Vddq1=Vddq2 = Vddq3 = Vddq4 = VddL1 =VddL2= 3.3V) or (Vddq1= Vddq2 = Vddq3=Vddq4 = 3.3V, VddL1 = VddL2 = 2.5V)

• < 250ps skew among CPU and SDRAM clocks

• < 250ps skew among PCI clocks

• < 5ns propagation delay SDRAM from buffer input

• Skew from CPU (earlier) to PCI clock 1 to 4ns, center 2.6ns.

• Smooth frequency switch with selections from 66 MHz to 200 MHz CPU

• Step-less frequency programming by controlling the VCO freq. and the clock output divisor ratio

• I2C 2-Wire serial interface and I2C read back

• ±0.25 or ±0.5 spread spectrum function to reduce EMI in freq. table mode

• Programmable spread spectrum in the M/N step-less mode

• Programmable registers to enable/stop each output and select modes

• MODE pin for power Management

• RESET# out when watch dog timer time out

• One 48 MHz for USB & one 24 MHz for super I/O

• 48-pin SSOP package