W83195BR-25
200MHZ 3-DIMM CLOCK FOR SOLANO CHIPSET
1.0 GENERAL DESCRIPTION
The W83195BR-25 is a Clock Synthesizer for Intel 815 Solano chipset. W83195BR-25 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 W83195BR-25 provides I
2
C serial bus interface to program the registers to enable or disable
each clock outputs and provides 0.25% and 0.5% center type spread spectrum to reduce EMI.
The W83195BR-25 provides stepless frequency programming by controlling the VCO freq. and the
clock output divisor ratio. Also skew of CPU,SDRAM and 3V66 clock outputs are programmable. A
watch dog timer is quipped and when time out, the RESET# pin will output 4ms pulse signal.
The W83195BR-25 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 as
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
•
•
•
•
•
•
•
•
•
•
•
•
•
2 CPU clocks (2.5V)
3 3V-66 clocks (3.3V)
12 SDRAM clocks for 3 DIMMs(3.3V)
8 PCI synchronous clocks.
Optional single or mixed supply:
(VDDR = VDDP=VDDS = VDD48 = VDD3 = 3.3V, VDDA=VDDC=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 200MHz
I
2
C 2-Wire serial interface and I
2
C read back
0.25% center and
0.5% center type
spread spectrum
Programmable registers to enable/stop each output and select modes
(mode as Tri-state or Normal )
48 MHz for USB
24 MHz for super I/O
Packaged in 56-pin SSOP
-1-
Publication Release Date: May 2000
Revision 0.52
WINBOND [ WINBOND ]
