EMC2103 Standard Microsystems Corporation, EMC2103 Datasheet - Page 26

• Manufacturer Part Number: EMC2103
• Description: Rpm-based Fan Controller with HW Thermal Shutdown
• Manufacturer: Standard Microsystems Corporation

Revision 0.85 (01-29-08)
5.4.1
T4 - Hyst
T3 - Hyst
T2 - Hyst
T5 - Hyst
T6 - Hyst
Temp
T5
T6
T4
T3
T2
T1
Programming the Look Up Table
When the Look Up Table is used, it must be loaded and configured correctly based on the system
requirements. The following steps outline the procedure.
1. Determine whether the Look Up Table will drive a PWM duty cycle or a tachometer target value
2. Determine which measurement channels (up to four) are to be used with the Look Up Table and
3. For each step to be used in the LUT, set the Fan Setting (either PWM or TACH Target as set by
4. For each step to be used in the LUT, set each of the measurement channel thresholds. These
5. Update the threshold hysteresis to be smaller than the smallest table step.
6. Configure the RPM based Fan Speed Control Algorithm if it is to be used. See
and set the RPM / PWM bit in the Fan LUT Configuration Register (see
set the TEMP3_CFG and TEMP4_CFG bits accordingly in the Fan LUT Configuration Register.
the RPM / PWM bit). If a setting is not used, then set it to FFh (if a PWM) or 00h (if a TACH Target).
Load the lowest settings first in ascending order (i.e. Fan Setting 1 is the lowest setting greater
than “off”. Fan Setting 2 is the next highest setting, etc.). See
values must be set in the same data format that the data is presented. If DTS is to be used, then
the format should be in temperature with a maximum threshold of 100°C (64h). If a measurement
channel is not used, then set the threshold at FFh.
more details.
Temperature
Averaged
Figure 5.3 Fan Control Look-Up Table Example
Setting
Fan
DATASHEET
Measurement taken
26
Time
RPM-Based Fan Controller with HW Thermal Shutdown
Section
6.33.
Section
6.32).
Section 5.5.1
SMSC EMC2103
Setting
Datasheet
S6
S4
S3
S2
S1
S5
Fan
for