emc2105 Standard Microsystems Corp., emc2105 Datasheet - Page 28

• Manufacturer Part Number: emc2105
• Description: Emc2105 Rpm-based High Side Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

Revision 1.74 (05-08-08)
5.4.1
T4 - Hyst
T3 - Hyst
T2 - Hyst
T5 - Hyst
T6 - Hyst
T8 - Hyst
T7 - Hyst
Temp
T5
T6
T4
T3
T2
T1
T8
T7
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 fan setting or a tachometer target value and set
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 fan setting or TACH Target as set
4. For each step to be used in the LUT, set each of the measurement channel thresholds. These
the TACH / DRIVE bit in the Fan LUT Configuration Register.
set the TEMP3_CFG and TEMP4_CFG bits accordingly in the Fan LUT Configuration Register.
by the TACH / DRIVE bit). If a setting is not used, then set it to FFh (if a fan setting) 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.).
values must be set in the same data format that the data is presented. If DTS is to be used, then
Temperature
Averaged
Figure 5.3 Fan Control Look-Up Table Example
Setting
Fan
Measurement taken
DATASHEET
RPM-Based High Side Fan Controller with Hardware Thermal Shutdown
28
Time
SMSC EMC2105
Datasheet
Setting
S6
S4
S3
S2
S1
S8
S7
S5
Fan