Dual RPM-Based PWM Fan Controller
Datasheet
Table 5.1 EMC2302 Register Set (continued)
FUNCTION
REGISTER
NAME
DEFAULT
VALUE
ADDR
R/W
LOCK
PAGE
Fan 1 Spin Up
Configuration
Sets the configuration values for Spin
Up Routine of the Fan 1 driver
36h
R/W
19h
SWL
Page 33
Sets the maximum change per update
37h
38h
39h
3Ah
3Bh
3Ch
3Dh
3Eh
3Fh
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
Fan 1 Max Step
10h
SWL
SWL
SWL
SWL
SWL
No
Page 35
Page 36
Page 36
for the Fan 1 driver
Fan 1 Minimum
Drive
Sets the minimum drive value for the
Fan 1 driver
66h
(40%)
Fan 1 Valid TACH
Count
Holds the tachometer reading that
indicates Fan 1 is spinning properly
F5h
00h
00h
F8h
FFh
FFh
F8h
Fan 1 Drive Fail
Band Low Byte
Stores the number of Tach counts used
to determine how the actual fan speed
must match the target fan speed at full
scale drive
Page 37
Fan 1 Drive Fail
Band High Byte
TACH 1 Target
Low Byte
Holds the target tachometer reading low
byte for Fan 1
Page 37
Page 37
Page 38
Page 38
TACH 1 Target
High Byte
Holds the target tachometer reading
high byte for Fan 1
No
TACH 1 Reading
High Byte
Holds the tachometer reading high byte
for Fan 1
No
TACH 1 Reading
Low Byte
Holds the tachometer reading low byte
for Fan 1
R
No
Fan 2 Control Registers
Always displays the most recent fan
driver input setting for Fan 2. If the
RPM-based Fan Speed Control
Algorithm is disabled, allows direct user
control of the fan driver.
40h
R/W
Fan 2 Setting
PWM 2 Divide
00h
No
Page 29
Stores the divide ratio to set the
frequency for Fan 2
41h
42h
43h
45h
R/W
R/W
R/W
R/W
01h
2Bh
28h
2Ah
No
No
Page 29
Page 30
Page 31
Page 33
Sets configuration values for the RPM-
based Fan Speed Control Algorithm for
Fan 2
Fan 2
Configuration1
Fan 2
Configuration 2
Sets additional configuration values for
the Fan 2 driver
SWL
SWL
Holds the gain terms used by the RPM-
based Fan Speed Control Algorithm for
Fan 2
Gain 2
Fan 2 Spin Up
Configuration
Sets the configuration values for Spin
Up Routine of the Fan 2 driver
46h
47h
48h
R/W
R/W
R/W
19h
10h
SWL
SWL
SWL
Page 33
Page 35
Page 36
Sets the maximum change per update
for Fan 2
Fan 2 Max Step
Fan 2 Minimum
Drive
Sets the minimum drive value for the
Fan 2 driver
66h
(40%)
Revision 1.1 (10-12-09)
SMSC EMC2302
DATA2S4HEET
SMSC [ SMSC CORPORATION ]
