EMC6D103-CK SMSC [SMSC Corporation], EMC6D103-CK Datasheet - Page 67

• Manufacturer Part Number: EMC6D103-CK
• Description: FAN CONTROL DEVICE WITH HIGH FREQUENCY PWM
• Manufacturer: SMSC [SMSC Corporation]

Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
Datasheet
SMSC EMC6D103
8.2.16
Register
Address
5Fh
60h
61h
Temperature
Below Fan Temp Limit: Fan is off or at Fan PWM
Minimum depending on bit[7:5] of register 62h
Read/
Write
R/W
R/W
R/W
Registers 5F-61h: Zone Temperature Range, PWM Frequency
These registers become read only when the Lock bit is set. Any further attempts to write to these
registers shall have no effect.
In Auto Fan Mode, when the temperature for a zone is above the Low Temperature Limit (registers
67-69h) and below the Absolute Temperature Limit (registers 6A-6Ch) the speed of a fan assigned to
that zone is determined as follows by the auto fan control logic.
When the temperature reaches the temperature value programmed in the Zone x Low Temp Limit
register, the PWM output assigned to that zone is at PWMx Minimum Duty Cycle. Between Zone x
Low Temp Limit and (Zone x Low Temp Limit + Zone x Range), the PWM duty cycle increases linearly
according to the temperature as shown in the figure below.
Table 8.27 Registers 5F-61h: Zone Temperature Range, PWM Frequency
Zone 1 Range / Fan 1
Zone 2 Range / Fan 2
Zone 3 Range / Fan 3
and bit 2 of register 7Fh
Register Name
Frequency
Frequency
Frequency
Figure 8.1 Fan Activity Above Fan Temp Limit
SPIN[2:0]
000
001
010
100
101
011
110
111
Table 8.26 Fan Spin-Up Register
(MSb)
RAN3
RAN3
RAN3
Bit 7
output at MIN FAN SPEED
Temperature LIMIT: PWM
DATASHEET
RAN2
RAN2
RAN2
Bit 6
67
RAN1
RAN1
RAN1
Bit 5
250ms (default)
SPIN UP TIME
RAN0
RAN0
RAN0
1000ms
2000ms
4000ms
Bit 4
100ms
400ms
700ms
PWM Duty is linear over
0 sec
this range
FRQ3
FRQ3
FRQ3
Bit 3
FRQ2
FRQ2
FRQ2
Bit 2
LIMIT+ RANGE: PWM
Output at 100% Duty
FRQ1
FRQ1
FRQ1
Bit 1
Revision 0.4 (04-04-05)
(LSb)
FRQ0
FRQ0
FRQ0
Bit 0
Default
Value
C3h
C3h
C3h