emc2104 Standard Microsystems Corp., emc2104 Datasheet - Page 93

• Manufacturer Part Number: emc2104
• Description: Emc2104 Dual Rpm-based Pwm Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

ADDR
22h
42h
46h
50h
Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown
Datasheet
SMSC EMC2104
B.2
STEP #
SPEED
FAN
1
2
3
4
5
Configuration
3
Configuration
Configuration
Configuration
REGISTER
Fan 1 Spin
LUT 1
Fan 1
EXTERNAL DIODE
Up
1 TEMPERATURE
1
Example #2
This example uses the RPM based Fan Speed Control Algorithm. The Spin Level (used by the Spin
Up Routine) should be changed to 50% drive for a total Spin Time of 1 second. For all other RPM
configuration settings, the default conditions are used.
For control inputs, it uses the External Diode 1 channel normally, a thermistor input on the External
Diode 2 channel, the internal diode channel, and a Pushed Temperature that represents the MCU
temperature in standard format. The configuration is set as shown in
how the table is loaded.
Note that when using Thermistor data, the VIN2_INV bit should be set. The circuitry will automatically
subtract the measured thermistor voltage from a quantity of FFh (effectively inverting it). Therefore, the
Look Up Table is loaded with ascending voltage thresholds with respect to the drive settings.
Additionally, the reading register will show this same value (subtracted from FFh).
(CPU)
35
40
50
60
70
o
o
o
o
o
C
C
C
C
C
-
DRIVE_FAIL_CNT
USE_D
TS_F1
ALGO
EN_
B7
1
0
0
-
1 [1:0]
Table B.5 Look Up Table Example #2 Configuration
Table B.6 Fan Speed Control Table Example #2
THERMISTOR 2
VIN4_I
NV
USE_D
TS_F2
B6
178.125mV
203.125mV
253.125mV
228.125mV
VOLTAGE
READING
156.25mV
0
1
0
0
RANGE[1:0]
(45°C)
(50°C)
(55°C)
(60°C)
(65°C)
VIN3_E
N
NOKICK
LUT_LO
CK
B5
DATASHEET
0
0
1
0
1
TEMPERATURE
93
VIN3_I
NV
TACH /
DRIVE
SETTING
PUSHED
B4
EDGES[1:0]
0
0
0
0
30
35
40
45
50
SPIN_LVL[2:0]
o
o
o
o
o
C
C
C
C
C
VIN2_
EN
1
TEMP3_CFG
B3
1
1
1
[1:0]
INTERNAL DIODE
VIN2_I
NV
TEMPERATURE
B2
1
0
0
0
(AMBIENT)
Table B.5
40
45
50
55
60
UPDATE[2:0]
o
o
o
o
o
C
C
C
C
C
VIN1_
EN
0
SPINUP_TIME
TEMP4_CFG
B1
1
1
0
while
Revision 1.74 (05-08-08)
[1:0]
[1:0]
VIN1_I
NV
0
Table B.6
B0
1
0
0
(1007 RPM)
(2048 RPM)
(3072 RPM)
(4096 RPM)
(5120 RPM)
TARGET
TACH
3Dh
1Eh
0Ch
14h
0Fh
SETTING
shows
CBh
0Ch
0Ah
28h