emc2105 Standard Microsystems Corp., emc2105 Datasheet - Page 63

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

ADDR
RPM-Based High Side Fan Controller with Hardware Thermal Shutdown
Datasheet
47h
SMSC EMC2105
6.23
R/W
R/W
2
0
0
0
0
1
1
1
1
Bits 4 - 2 - SPIN_LVL[2:0] - Determines the final drive level that is used by the Spin Up Routine as
shown in
Bit 1 -0 - SPINUP_TIME[1:0] - determines the maximum Spin Time that the Spin Up Routine will run
for (see
elapsed, then an interrupt will be generated. When the RPM based Fan Speed Control Algorithm is
active, the fan driver will attempt to re-start the fan immediately after the end of the last spin up attempt.
The Spin Time is set as shown in
The Fan Step Register, along with the Update Time, controls the ramp rate of the fan driver response
calculated by the RPM based Fan Speed Control Algorithm. The value of the registers represents the
maximum step size each fan driver will take between update times (see
Fan Step Register
1
0
0
1
1
Fan Max Step
REGISTER
Section
Table
6.35.
SPIN_LVL[2:0]
6.9). If a valid tachometer measurement is not detected before the Spin Time has
SPINUP_TIME[1:0]
B7
1
0
0
1
1
0
0
1
1
-
Table 6.37 Fan Step Register
Table 6.35 Spin Level
Table 6.36 Spin Time
B6
Table
-
DATASHEET
6.36.
B5
32
63
0
0
1
0
1
B4
16
0
0
1
0
1
0
1
0
1
B3
8
B2
4
SPIN UP DRIVE LEVEL
Section
TOTAL SPIN UP TIME
B1
2
60% (default)
500 ms (default)
Revision 1.74 (05-08-08)
30%
35%
40%
45%
50%
55%
65%
250 ms
6.19).
1 sec
2 sec
B0
1
DEFAULT
10h