EMC2305 Datasheet, PDF (27/55 Pages) SMSC Corporation – Multiple RPM-Based PWM Fan Controller for Five Fans

Multiple RPM-Based PWM Fan Controller for Five Fans
Datasheet
Table 5.1 EMC2305 Register Set (continued)
ADDR
35h
36h
37h
38h
39h
3Ah
3Bh
3Ch
3Dh
3Eh
3Fh
40h
41h
42h
43h
45h
46h
47h
REGISTER
R/W
NAME
R/W
Gain 1
R/W
Fan 1 Spin Up
Configuration
R/W Fan 1 Max Step
R/W
Fan 1 Minimum
Drive
R/W
Fan 1 Valid TACH
Count
R/W
Fan 1 Drive Fail
Band Low Byte
R/W
Fan 1 Drive Fail
Band High Byte
R/W
TACH 1 Target
Low Byte
R/W
TACH 1 Target
High Byte
R
TACH 1 Reading
High Byte
R
TACH 1 Reading
Low Byte
R/W Fan 2 Setting
R/W PWM 2 Divide
R/W
Fan 2
Configuration1
R/W
Fan 2
Configuration 2
R/W
Gain 2
R/W
Fan 2 Spin Up
Configuration
R/W Fan 2 Max Step
FUNCTION
DEFAULT
VALUE LOCK
Holds the gain terms used by the RPM-
based Fan Speed Control Algorithm for
2Ah
the Fan 1 driver
SWL
Sets the configuration values for Spin
Up Routine of the Fan 1 driver
19h
SWL
Sets the maximum change per update
for the Fan 1 driver
10h
SWL
Sets the minimum drive value for the
Fan 1 driver
66h
(40%)
SWL
Holds the tachometer reading that
indicates Fan 1 is spinning properly
F5h
SWL
Stores the number of Tach counts used
00h
SWL
to determine how the actual fan speed
must match the target fan speed at full
scale drive
00h
SWL
Holds the target tachometer reading low
byte for Fan 1
F8h
Holds the target tachometer reading
high byte for Fan 1
FFh
Holds the tachometer reading high byte
for Fan 1
FFh
Holds the tachometer reading low byte
for Fan 1
F8h
Fan 2 Control Registers
Always displays the most recent fan
driver input setting for Fan 2. If the
RPM-based Fan Speed Control
00h
Algorithm is disabled, allows direct user
control of the fan driver.
Stores the divide ratio to set the
frequency for Fan 2
01h
Sets configuration values for the RPM-
based Fan Speed Control Algorithm for
2Bh
Fan 2
Sets additional configuration values for
the Fan 2 driver
28h
Holds the gain terms used by the RPM-
based Fan Speed Control Algorithm for
2Ah
Fan 2
Sets the configuration values for Spin
Up Routine of the Fan 2 driver
19h
Sets the maximum change per update
for Fan 2
10h
No
No
No
No
No
No
No
SWL
SWL
SWL
SWL
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SMSC EMC2305
27
DATASHEET
Revision 1.1 (10-12-09)