W83627DHG Datasheet, PDF (54/268 Pages) Winbond – WINBOND LPC I/O

W83627DHG
Thermal Cruise^TM mode controls the fan speed to keep the temperature in a specified range. First, this
range is defined in BIOS by a temperature and the interval (e.g., 55 °C ± 3 °C). As long as the current
temperature remains below the low end of this range (i.e., 52 °C), the fan is off. Once the temperature
exceeds the low end, the fan turns on at a speed defined in BIOS (e.g., 20% output). Thermal Cruise^TM
mode then controls the fan output according to the current temperature. Three conditions may occur:
(1) If the temperature still exceeds the high end, fan output increases slowly. If the fan is operating
at full speed but the temperature still exceeds the high end, a warning message is issued to protect
the system.
(2) If the temperature falls below the high end (i.e., 58 °C) but remains above the low end (e.g., 52
°C), fan output remains the same.
(3) If the temperature falls below the low end (e.g., 52 °C), fan output decreases slowly to zero or to
a specified “stop value”. This stop value is enabled by Bank0 Index 12h, bits 3 ~ 5, and the value
itself is specified in Bank0 Index 08h, Index 09h, Index 15h, and Index 64h. The fan remains at the
stop value for the period of time defined in Bank0 Index 0Ch, Index 0Dh, Index 17h, and Index 66h.
In general, Thermal Cruise^TM mode means
• if the current temperature is higher than the high end, increase the fan speed;
• if the current temperature is lower than the low end, decrease the fan speed;
• otherwise, keep the fan speed the same.
The following figures illustrate two examples of Thermal Cruise^TM mode.
Publication Release Date: Aug, 22, 2007
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Version 1.4