W83194BR-KT

STEP-LESS 3-DIMM K7 CLOCK

Publication Release Date: June 2000

- 1 -

Revision 0.43

1.0 GENERAL DESCRIPTION

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

W83194BR-KT provides 64 CPU/PCI frequencies which are selectable with smooth transitions by

hardware or software. W83194BR-KT also provides 13 SDRAM clocks controlled by the none-delay

buffer_in pin.

The W83194BR-KT 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-KT 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 I

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.

2.0 PRODUCT FEATURES

• 3 CPU clocks (one free-running chipset clock controlled by I2C)

• 13 SDRAM clocks for 3 DIMMs

• 6 PCI synchronous clocks

• Optional single or mixed supply:

(Vddq2 =2.5V, Vddq3 =3.3V)

• < 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

•

I

• ±0.25% or ±0.5% spread spectrum function to reduce EMI

• 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 and RESET# out when Watch Dog Timer time out

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

• 48-pin SSOP package