W83627EHF Datasheet, PDF (41/141 Pages) Winbond – evolving product from Winbonds most popular I/O family

W83627EHF/EF, W83627EHG/EG
SMART FAN^TM III
Concept
SMART FAN^TM III mode sets a target temperature through BIOS or application software and
W83627EHF/EHG controls the fan speed so that the temperature could meet the target temperature
set in the BIOS or software. Only Pin115 (CPUFANOUT0) and Pin120 (CPUFANOUT1) in
W83627EHF/EHG support SMART FAN^TM III. Pin115 (CPUFANOUT0) pairs with Pin103 (CPUTIN);
while Pin120 (CPUFANOUT1) pairs with Pin104 (SYSTIN), Pin103 (CPUTIN), or Pin102 (AUXTIN),
which is defined in Bank0 Index 4Ah.bit7~6.
Pin 103
CPUTIN
Pin 104
SYSTIN
Pin 102
AUXTIN
Pin 115
CPUFanOut0
Pin 120
CPUFanOut1
Figure 6.9, 6.10, and 6.11 illustrate SMART FAN^TM III mode, and the algorithm of fan speed control
is described as follows:
(1) Figure 6.9 shows the initial condition of SMART FAN^TM III. Target Temperature, Temperature
Tolerance, Maximum Fan Output and Minimum Fan Output must be set first. If the currently
measured temperature is within the (Target Temperature ± Temperature Tolerance), the fan
speed remains constant.
(2) In the case that currently measured temperature goes beyond (Target Temperature ＋
Temperature Tolerance), which is shown in Figure 6.10, fan speed jumps up to the next step.
“Step” here refers to the value in the CPUFANOUT Output Value Select Register, Bank0 Index03h
or Index61h.
(3) Meanwhile, original Target Temperature dynamically shifts to (Target Temperature ＋
Temperature Tolerance), and new Target Temperature, named Target Temperature 1, is formed.
In other words, Target Temperature 1 equals original Target Temperature plus Temperature
Tolerance.
(4) If the currently measured temperature is within the (Target Temperature 1 ± Temperature
Tolerance) then, the fan speed remains constant. Otherwise, fan speed jumps up to the next step
again. Target Temperature then dynamically shifts to (Target Temperature 1 ＋ Temperature
Tolerance), and new Target Temperature again, named Target Temperature 2, is formed.
(5) The fan-speed-up and Target Temperature comparison-then-shift process continue until currently
measured temperature locates within (Target Temperature X ± Temperature Tolerance), or fan
output speed reaches its maximum speed.
Publication Release Date: January 18, 2006
-35-
Revision 1.0