w83795g Winbond Electronics Corp America, w83795g Datasheet - Page 105

• Manufacturer Part Number: w83795g
• Description: Nuvoton H/w Monitor
• Manufacturer: Winbond Electronics Corp America

10.1.2.4. Default Fan Speed at Power-on (DFSP)
DFSP (default fan peed at power-on) sets the initial speed of every fan. When the system is turned on,
a default will be given to all fan outputs according to the register content. This register is specially
designed to be reset by VSB only, so at the second system power on, the system will use the last setup
speed to turn on all of the fans.
Location:
Type:
Reset:
10.1.2.5. SmartFan Output Step Up Time (SFOSUT)
SFOSUT adjusts the time interval of the fan speed up by a unit. The default setting is 12.8sec.
Location: SFOSUT - Bank 2 Address 0D
Type:
Reset:
SmartFan is designed for the smooth operation of the fan. The fan duty is seldom suddenly increased
or decreased. Instead, most often the duty is increased or decreased by 1 LSB. The Up Time / Down
Time register defines the time interval between successive duty increases or decreases. If this value is
set too small, the fan will not have enough time to speed up after tuning the duty and sometimes may
result in unstable fan speed. On the other hand, if Up Time / Down Time is set too large, the fan may
not work fast enough to dissipate the heat. This register should never be set to 0. Otherwise, the fan
duty will be abnormal.
10.1.2.6. SmartFan Output Step Down Time (SFOSDT)
DEFAULT
DEFAULT
NAME
NAME
BIT
BIT
Only in the following cases will the fan duty soar or plummet.
3VDD Power – on/off
Fan Turn off state to Start
Fan at FONV (Fan Output Nonstop Value) to turn off state
Read / Write
Read / Write
Init Reset (CR01.Bit7) is set,
3VSB Rising,
3VSB Rising,
3VDD Rising @ RST_VDD_MD (CR01.Bit5) set,
SYSRSTIN# Falling @ SYSRST_MD (CR01.Bit6) set.
DefaultSpeed (Default Fan Speed at Power-on). Specifies the fan duty at next power
on.
UpTime (SmartFan Step Up Time). Unit in 0.1sec. Programmed as the interval of
continuous Fan ramping up.
DFSP - Bank 2 Address 0C
7
7
6
6
5
5
HEX
HEX
SFOSUT
- 105 –
DFSP
4
4
4D
80
HEX
HEX
3
3
2
2
W83795G/ADG
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1
Revision 1.41
Aug/2/2010
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