emc2101 Standard Microsystems Corp., emc2101 Datasheet - Page 42

• Manufacturer Part Number: emc2101
• Description: Emc2101 Fan Control With 1?c Accurate Temperature Monitoring
• Manufacturer: Standard Microsystems Corp.

Revision 2.53 (02-19-08)
6.18
ADDR.
4Ch
2
0
0
0
0
1
1
1
1
1
0
1
1
SPIN_DRIVE[1:0]
R/W
R/W
(see
text)
Bit 2-0 - SPIN_TIME[2:0] - determines the length of time that the fan drive will remain at the
SPIN_DRIVE[1:0] setting as shown in
The Fan Setting Register drives the fan driver when the Fan Control Look-Up Table is not used (see
Section
(PWM or DAC). When the Fan Control Look-Up Table is being used, any writes to this register will be
ignored. If the Fan Control Look-Up Table is disabled, then the fan drive will be set at the last value
that was used by the Fan Control Look-Up Table.
When the Fan Control Look-Up Table Registers are being used, the register is read-only.
The register applies to the fan driver in both PWM and DAC operating modes. The DAC output is
determined by equation
Fan Setting Register
SPIN_TIME[2:0]
6.16). Any data written to the Fan Setting registers is applied immediately to the fan driver
Fan Setting
REGISTER
1
0
0
1
1
0
0
1
1
0
1
0
1
[4]
B7
-
Table 6.23 Fan Setting Register
50% (half drive)
75% (3/4 drive)
100% (full drive) (default)
below.
0
0
1
0
1
0
1
0
1
Table 6.21 Spin-Up Drive
Table 6.22 Spin-Up Time
B6
-
DATASHEET
Table
0 - Spin-Up Cycle bypassed
0.05 sec.
0.1 sec.
0.2 sec.
0.4 sec.
0.8 sec.
1.6 sec.
3.2 sec. (default)
B5
32
42
6.22.
SMBus Fan Control with 1°C Accurate Temperature Monitoring
B4
16
SPIN UP DRIVE
B3
8
SPIN UP TIME
B2
4
B1
2
B0
1
SMSC EMC2101
DEFAULT
Datasheet
00h