SMBus Fan Control with 1°C Accurate Temperature Monitoring
Datasheet
Table 6.1 Register Set in Hexadecimal Order (continued)
REGISTER
ADDRESS
DEFAULT
VALUE
R/W
R/W
REGISTER NAME
FUNCTION
PAGE
17h
18h
External Diode Ideality
Factor
Sets ideality factor based
on diode type
12h
(1.008)
Page 37
R/W
R/W
R/W
R
Beta Compensation Factor
Compensates for
transistors with various
beta factors
08h
Page 38
Page 35
Page 35
Page 39
19h
21h
46h
TCRIT Temp Limit
Fan will be set to full speed
if external temp above this
value
55h
(85°C)
TCRIT Hysteresis
Amount of hysteresis
applied to TCRIT Temp
(1LSB = 1°C)
0Ah
(10°C)
TACH Reading Low Byte
Stores the lower 6 bits of
the TACH count. and the
TACH configuration bits
FFh
47h
48h
49h
4Ah
R
TACH Reading High Byte
TACH Limit Low Byte
TACH Limit High Byte
FAN Configuration
Stores the upper 8 bits of
the TACH count.
FFh
FFh
FFh
20h
Page 39
Page 39
Page 39
Page 40
R/W
R/W
R/W
Stores the lower 6 bits of
the TACH Limit
Stores the upper 8 bits of
the TACH Limit
defines polarity of PWM or
DAC
4Bh
4Ch
4Dh
R/W
R/W
R/W
Fan Spin-up
Sets Spin Up options
3Fh
00h
17h
Page 41
Page 42
Page 43
Fan Setting
Sets PWM or DAC value
PWM Frequency
Sets the final PWM
Frequency
4Eh
4Fh
R/W
R/W
PWM Frequency Divide
Lookup Table Hysteresis
Sets the base PWM
frequency
01h
Page 43
Page 44
Amount of hysteresis
applied to Lookup Table
Temp (1LSB = 1°C)
04h
(4°C)
R/W (See
Note 6.1)
Lookup Table Temp Setting 1 Look Up Table
Temperature Setting 1
7Fh
3Fh
7Fh
3Fh
7Fh
3Fh
Page 45
Page 45
Page 45
Page 45
Page 45
Page 45
50h
51h
R/W (See
Note 6.1)
Lookup Table Fan Setting 1
Associated Fan Setting for
Temp Setting 1
52h
53h
54h
55h
R/W (See
Note 6.1)
Lookup Table Temp Setting 2 Look Up Table
Temperature Setting 2
R/W (See
Note 6.1)
Lookup Table Fan Setting 2
Associated Fan Setting for
Temp Setting 2
R/W (See
Note 6.1)
Lookup Table Temp Setting 3 Look Up Table
Temperature Setting 3
R/W (See
Note 6.1)
Lookup Table Fan Setting 3
Associated Fan Setting for
Temp Setting 3
Revision 2.53 (03-13-07)
SMSC EMC2101
DATA3S0HEET
SMSC [ SMSC CORPORATION ]
