F81866A Datasheet, PDF (38/210 Pages) Feature Integration Technology Inc. – 6 UARTs Super IO With 128 Bytes FIFO and Power

FAN 2
FAN_PROG_SEL
FAN Type Select
FAN mode Select
FAN count reading
FAN expect speed
FAN full speed count
BOUNDARY
SEGMENT SPEED
FAN1 Temperature Mapping
Related Register
Index 9Fh [7]
Index 94 [3:2]
Index 96 [3:2]
Index B0h~B1h
Index B2h~B3h
Index B4h~B5h
Index B6h~B9h
Index BAh~BEh
Index BFh
F81866A
FAN 3
CLK_TUNE_PROG_EN
Multi Function
FAN_PROG_SEL
FAN Type Select
FAN mode Select
FAN count reading
FAN expect speed
FAN full speed count
BOUNDARY
SEGMENT SPEED
FAN1 Temperature Mapping
Related Register
Global Control Register : index 27h [0]
Global Control Register : index 2Bh [1:0]
Index 9Fh [7]
Index 94 [5:4]
Index 96 [5:4]
Index C0h~C1h
Index C2h~C3h
Index C4h~C5h
Index C6h~C9h
Index CAh~CEh
Index CFh
(1) Manual mode
For manual mode, it generally acts as the software fan speed control.
(2) Auto mode
In auto mode, the F81866A provides the automatic fan speed control related to the temperature
variation of CPU/GPU or the system. The F81866A can provide four temperature boundaries and five
intervals, and each interval has its related fan speed count. All these values should be set by BIOS
first. Take FAN1 for example, the 4 temperature boundaries could be set from the register 0xA6 to
0xA9 and the five intervals for fan speed control could be set from register 0xAA to 0xAE.The
hysteresis setting (0 ~ 15°C) could also be found in the register 0x98.
There are two kinds for the auto modes they are the stage auto mode and the linear auto mode.
The “FAN1_INTERPOLATION_EN” in the register 0xAFh is used for the linear auto mode enable.
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Jan, 2012
V0. 12P