W83194R-58A

100MHZ AGP CLOCK FOR VIA CHIPSET

Publication Release Date: Nov. 1999

- 1 -

Revision 0.30

1.0 GENERAL DESCRIPTION

The W83194R-58A is a Clock Synthesizer for VIA chipset.

W83194R-58A provides all clocks

required for high-speed RISC or CISC microprocessor such as Intel PentiumII and also provides 16

different frequencies of CPU clocks by software setting.

AGP and PCI clocks are externally

selectable with smooth transitions.

The W83194R-58A provides AGP clocks especially for clone

chipset, and makes SDRAM in synchronous frequency with CPU or AGP clocks.

The W83194R-58A provides I

each clock outputs and choose the 0.25%, 0.5% or 0.5%,1.5% center type spread spectrum to reduce

EMI.

The W83194R-58A 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

pF loads. CPU CLOCK outputs typically provide better than 1 V /ns slew rate into 20 pF loads when

maintaining 50± 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

• 4 CPU clocks

• 12 SDRAM clocks for 3 DIMs

• Two AGP clocks

• 6 PCI synchronous clocks.

• Optional single or mixed supply:

(Vdd = Vddq3 = Vddq2 = Vddq2b = 3.3V) or (Vdd = Vddq3 = Vddq2 = 3.3V, Vdq2b = 2.5V)

•

Skew form CPU to PCI clock -1 to 4 ns, center 2.6 ns, AGP to CPU sync. skew 0 ns (250 ps)

•

SDRAM frequency synchronous to CPU or AGP clocks

•

Smooth frequency switch with selections from 60 to 100 MHz CPU(-37) and 66 to 150MHz(-58)

•

0~0.5% down type and 0.25%, 0.5% center type spread spectrum to reduce EMI

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

(mode as Tri-state or Normal )

• MODE pin for power Management

• 48 MHz for USB

• 24 MHz for super I/O

• 48-pin SSOP package