Fan Control Device with Hardware Monitoring and Acoustic Noise Reduction Features
Datasheet
Table 7.15 Absolute Limit vs. Register Setting
ABSOLUTE LIMIT
ABS LIMIT (DEC)
ABS LIMIT (HEX)
-127°c
-127
81h
.
.
.
.
.
.
.
.
.
-50°c
-50
CEh
.
.
.
.
.
.
.
.
.
0°c
0
00h
.
.
.
.
.
.
.
.
.
50°c
50
32h
.
.
.
.
.
.
.
.
.
127°c
127
7Fh
7.2.22
Registers 6D-6Eh: Zone Hysteresis Registers
Register
Address
Read/
Write
Bit 7
Bit 0
Default
Value
Register Name
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
(MSb)
(LSb)
H2-0
RES
6Dh
6Eh
R/W
R/W
Zone 1, Zone 2 Hysteresis
Zone 3, Hysteresis
H1-3
H3-3
H1-2
H3-2
H1-1
H3-1
H1-0
H3-0
H2-3
RES
H2-2
RES
H2-1
RES
44h
40h
These registers become read only when the Lock bit is set. Any further attempts to write to these
registers shall have no effect.
If the temperature is above the Zone x Low Temp Limit, then drops below Zone x Low Temp Limit, the
following will occur:
The fan will remain on, at Fan PWM Minimum, until the temperature goes a certain amount below the
associated zones low temperature limit (see Zone x Low Temp Limit registers). That is, when the
temperature is less than the temperature limit minus the hysteresis value, the fan will turn off.
The Hysteresis registers control this amount. See below table for details.
Table 7.16 Hysteresis Settings
SETTING
HYSTERESIS
0h
0°C
.
.
.
.
.
5h
5°C
.
.
.
.
.
.
Fh
15°C
Revision 0.4 (04-05-05)
SMSC EMC6D102
DATA6S6HEET
SMSC [ SMSC CORPORATION ]
