W83194BR-KX

Features:

The W83194BR-KX is a Clock Synthesizer which provides all clocks required for AMD K7.

W83194BR-KX provides 64 CPU/PCI frequencies which are selectable with smooth transitions by hardware or software. W83194BR-KX also provides 13 SDRAM clocks controlled by the none-delay buffer_in pin.

The W83194BR-KX provides step-less frequency programming by controlling the VCO freq. and the programmable PCI clock output divisor ratio. A watchdog timer is quipped and when time out, the RESET# pin will output 4ms pulse signal.

The W83194BR-KX accepts a 14.318 MHz reference crystal as its input. Spread spectrum built in at ±0.5% or ±0.25% to reduce EMI. Programmable stopping individual clock outputs and frequency selection through I2C interface. The device meets the Pentium power-up stabilization, which requires CPU and PCI clocks be stable within 2 ms after power-up. Using dual function pin for the slots (ISA, PCI, CPU, DIMM) is not recommend.

Pinout




Description

·  Supports AMD CPU with I²C.
·  3 CPU clocks (one free-running chipset clock controlled by I²C)
·  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 = VdqL2 = 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
·  Stepless frequency programming by controlling the VCO freq. and the clock output divisor ratio
·  Programmable skew and driving strength for CPU and SDRAM clock outputs
·  I²C 2-Wire serial interface and I²C read back
·  ±0.25% or ±0.5% spread spectrum function to reduce EMI
·  Programmable registers to enable/stop each output and select modes
·  MODE pin for power Management and RESET# out when system hang
·  One 48 MHz for USB & one 24 MHz for super I/O
·  48-pin SSOP package