
W83627UHG
If the current temperature rises higher than (Target Temperature 1 + Temperature Tolerance), the fan
speed rises one step again, and the target temperature shifts to (Target Temperature 1 + Temperature
Tolerance), or Target Temperature 2. This process repeats whenever the current temperature is
higher than (Target Temperature X ± Temperature Tolerance) or until the fan speed reaches its
maximum speed.
(4) If the current temperature falls below (Target Temperature - Temperature Tolerance), the fan
speed falls one step. The step is the value in the CPUFANOUT Output Value Select Register,
Bank0, Index 03h. In addition, the target temperature shifts to (Target Temperature -
Temperature Tolerance), creating a new target temperature named Target Temperature 1.This is
illustrated in the figure below.
Current Temp. < Target Temp.-
Current Temp. < Target Temp.- Tol.
Tol.
Fan output
Publication Release Date: March 24, 2008
-42-
Revision 1.44
Figure 7-16 SMART FAN
TM III Mechanism (Current Temp. < Target Temp. – Tol.)
If the current temperature falls lower than (Target Temperature 1 - Temperature Tolerance), the fan
speed is reduced one step again, and the target temperature shifts to (Target Temperature 1 -
Temperature Tolerance), or Target Temperature 2. This process repeats whenever the current
temperature is lower than (Target Temperature X - Temperature Tolerance) or until the fan speed
reaches its minimum speed.
(5) If the current temperature is always lower than (Target Temperature X - Temperature Tolerance),
the fan speed decreases slowly to zero or to a specified stop value. The stop value is enabled by
register Bank0, 12h, bit 4 and the stop value is specified in Bank0, Index 09h. The fan remains at
the stop value for the period of time defined in Bank0, Index 0Dh.
The following tables show the current temperature, fan output value and the relative control registers
at SMART FAN
TM III mode.
Min. Fan Output
Max. Fan Output
(DC / PWM)
Fan output
Tolerance
Temperature
Tar
Tar 1
Tar 2
Tar 3
Step
Tolerance
(DC / PWM)
Fan Initial
Output Value
Min. Fan Output
Max. Fan Output
Temperature
Tar
Fan Initial
Output Value
Step
Tar 2
Tar 3
Tar 1