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
Manual Mode
RPM
Duty
RPM
Duty
Step3: Set temp. follows
FAN1 :CRAF
Step3: Set temp. follows
FAN1 :CRAF
Step3: Set RPM
FAN1 :CR A2,A3
FAN2 :CR B2,B3
FAN3 :CR C2,C3
Step3: Set Duty
FAN1 :CR,A3
FAN2 :CR B3
FAN3 :CR C3
FAN2 :CRBF
FAN3 :CRCF
FAN2 :CRBF
FAN3 :CRCF
Step4: Set H/W Monitor
Fan1 – (BOUNDARY :CR A6~A9)
(SPEED : CR AA ~ AE)
Step4: Set H/W Monitor
Fan1 – (BOUNDARY :CR A6~A9)
(SPEED : CR AA ~ AE)
Fan2 –(BOUNDARY :CR B6~B9)
(SPEED : CR BA ~ BE)
Fan2 –(BOUNDARY :CR B6~B9)
(SPEED : CR BA ~ BE)
Fan3 –(BOUNDARY :CR C6~C9)
(SPEED : CR CA ~ CE)
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
FAN_PROG_SEL
FAN Type Select
Related Register
Index 9Fh [7]
Index 94 [1:0]
Index 96 [1:0]
Index A0h~A1h
Index A2h~A3h
Index A4h~A5h
Index A6h~A9h
Index AAh~AEh
Index AFh
FAN mode Select
FAN count reading
FAN expect speed
FAN full speed count
BOUNDARY
SEGMENT SPEED
FAN1 Temperature Mapping
37
Jan, 2012
V0. 12P
FINTEK [ FEATURE INTEGRATION TECHNOLOGY INC. ]
