W83627EHF Datasheet, PDF (42/141 Pages) Winbond – evolving product from Winbonds most popular I/O family

W83627EHF/EF, W83627EHG/EG
(6) Please be noted that “Speed-up Slope” shown in the Figure 6.10 must be an integer. In other
words, ^{Max.FanOutput − InitialOutput} must be an integer; otherwise, it may lead to register overflow.
Steps
(7) In the case that currently measured temperature goes below (Target Temperature － Temperature
Tolerance), which is shown in Figure 6.11, fan speed slows down by one step. “Step” here refers
to the value in the CPUFANOUT Output Value Select Register, Bank0 Index03h or Index61h.
(8) 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 minus Temperature
Tolerance.
(9) If the currently measured temperature is within the (Target Temperature 1 ± Temperature
Tolerance) then, the fan speed remains constant. Otherwise, fan speed slows down by one step
again. Target Temperature then dynamically shifts to (Target Temperature 1 － Temperature
Tolerance), and new Target Temperature again, named Target Temperature 2, is formed.
(10) The fan-slow-down and Target Temperature comparison-then-shift process continue until
currently measured temperature locates within (Target Temperature X ± Temperature Tolerance),
or fan output speed hits its minimum speed.
(11) Please be noted that “Speed-down Slope” shown in the Figure 6.11 must be an integer. In other
words, ^{InitialOutput − Min.FanOutput} must be an integer; otherwise, it may lead to register overflow.
Step
(12) In the case that the temperature is always lower than (Target Temperature X － Temperature
Tolerance), and, for some reason, the fan speed would like to be kept at the minimum speed, Stop
Value, instead of being stopped, set register Bank0 12h.bit 4. Set bit 4 to 1, fan speed will always
keep at the value set in Bank0 Index09h when temperature is always below (Target Temperature
X － Temperature Tolerance). Set bit 4 to 0, fan speed will decrease to 0 after a time period set in
Bank0 Index0Dh.
Fan output
(DC / PWM)
Setting
Tolerance
Max. Fan Output
Min. Fan Output
Tar. - Tol.
Tar. + Tol.
Figure 6.9
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Temperature