F81866A Datasheet, PDF (37/210 Pages) Feature Integration Technology Inc. – 6 UARTs Super IO With 128 Bytes FIFO and Power

F81866A
Fan speed control mechanism
There are some modes to control fan speed and they are 1.Manual mode, 2. Auto mode (Stage
& Linear). More detail, please refer to the description of registers & below figure.
Start
Step1: Select FAN_TYPE
(CR94)
DAC (linear)
PWM
Step2 :Select FAN_MODE
CR96 [5:4] Fan3
CR96 [3:2] Fan2
CR96 [1:0] Fan1
Auto Mode
RPM
Duty
Step3: Set temp. follows
FAN1 :CRAF
FAN2 :CRBF
FAN3 :CRCF
Step3: Set temp. follows
FAN1 :CRAF
FAN2 :CRBF
FAN3 :CRCF
Manual Mode
RPM
Step3: Set RPM
FAN1 :CR A2,A3
FAN2 :CR B2,B3
FAN3 :CR C2,C3
Duty
Step3: Set Duty
FAN1 :CR,A3
FAN2 :CR B3
FAN3 :CR C3
Step4: Set H/W Monitor
Fan1 – (BOUNDARY :CR A6~A9)
(SPEED : CR AA ~ AE)
Fan2 –(BOUNDARY :CR B6~B9)
(SPEED : CR BA ~ BE)
Fan3 –(BOUNDARY :CR C6~C9)
(SPEED : CR CA ~ CE)
Step4: Set H/W Monitor
Fan1 – (BOUNDARY :CR A6~A9)
(SPEED : CR AA ~ AE)
Fan2 –(BOUNDARY :CR B6~B9)
(SPEED : CR BA ~ BE)
Fan3 –(BOUNDARY :CR C6~C9)
(SPEED : CR CA ~ CE)
Fig 6-7 Fan type & mode selection flow
Each fan can be controlled by 8 kinds of temperature inputs: (1) T1 temperature (2)
T2 temperature (3) T3 temperature (4) PECI temperature (5) 4 suits I2C master
temperature.
FAN 1
Related Register
FAN_PROG_SEL
Index 9Fh [7]
FAN Type Select
Index 94 [1:0]
FAN mode Select
Index 96 [1:0]
FAN count reading
Index A0h~A1h
FAN expect speed
Index A2h~A3h
FAN full speed count
Index A4h~A5h
BOUNDARY
Index A6h~A9h
SEGMENT SPEED
Index AAh~AEh
FAN1 Temperature Mapping
Index AFh
37
Jan, 2012
V0. 12P