emc2305 Standard Microsystems Corp., emc2305 Datasheet - Page 28

• Manufacturer Part Number: emc2305
• Description: Multiple Rpm-based Pwm Fan Controller For Five Fans
• Manufacturer: Standard Microsystems Corp.

Revision 1.2 (03-22-10)
ADDR
4Ah
4Bh
4Ch
4Dh
4Eh
4Fh
48h
49h
50h
51h
52h
53h
55h
56h
57h
58h
59h
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
Fan 2 Valid TACH
Fan 3 Valid TACH
TACH 2 Reading
TACH 2 Reading
Fan 2 Drive Fail
Fan 2 Drive Fail
Fan 3 Max Step
Band High Byte
Fan 2 Minimum
Fan 3 Minimum
Band Low Byte
Configuration 1
Configuration 2
TACH 2 Target
TACH 2 Target
Fan 3 Spin Up
PWM 3 Divide
Fan 3 Setting
Configuration
REGISTER
High Byte
High Byte
Low Byte
Low Byte
Gain 3
NAME
Count
Fan 3
Fan 3
Count
Drive
Drive
Table 5.1 EMC2305 Register Set (continued)
Stores the number of Tach counts used
Holds the target tachometer setting high
Holds the tachometer reading high byte
Algorithm is disabled, allows direct user
Holds the gain terms used by the RPM-
Holds the target tachometer setting low
based Fan Speed Control Algorithm for
based Fan Speed Control Algorithm for
must match the target fan speed at full
Sets configuration values for the RPM-
to determine how the actual fan speed
Holds the tachometer reading low byte
Sets additional configuration values for
Sets the maximum change per update
Sets the configuration values for Spin
Sets the minimum drive value for the
Sets the minimum drive value for the
Always displays the most recent fan
indicates Fan 2 is spinning properly
indicates Fan 3 is spinning properly
driver input setting for Fan 3. If the
Holds the tachometer reading that
Holds the tachometer reading that
Stores the divide ratio to set the
RPM-based Fan Speed Control
Up Routine of the Fan 3 driver
Fan 3 Control Registers
control of the fan driver.
DATASHEET
frequency for Fan 3
for the Fan 3 driver
the Fan 3 driver
the Fan 3 driver
the Fan 3 driver
byte for Fan 2
byte for Fan 2
Fan 2 driver
Fan 3 driver
FUNCTION
scale drive
for Fan 2
for Fan 2
28
Multiple RPM-Based PWM Fan Controller for Five Fans
DEFAULT
VALUE
(40%)
(40%)
2Bh
2Ah
66h
F5h
00h
00h
F8h
FFh
FFh
F8h
00h
01h
28h
19h
10h
66h
F5h
LOCK
SWL
SWL
SWL
SWL
SWL
SWL
SWL
SWL
SWL
SWL
No
No
No
No
No
No
No
SMSC EMC2305
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Datasheet
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