emc2106 Standard Microsystems Corp., emc2106 Datasheet - Page 69

• Manufacturer Part Number: emc2106
• Description: Emc2106 Dual Rpm-based Linear Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

ADDR
3Ch
3Dh
ADDR
Dual RPM-Based Linear Fan Controller with Hardware Thermal Shutdown
Datasheet
APPLICATION NOTE: If any of the External Diode 1, External Diode 2, External Diode 3 is configured to operate
SMSC EMC2106
6.23
40h
80h
R/W
R/W
R/W
R/W
R/W
R/W
The EMC2106 contains high limits for all temperature channels and voltage channels. If any
measurement meets or exceeds the high limit then the appropriate status bit is set and the ALERT#
pin are asserted (if enabled).
Additionally, the EMC2106 contains low limits for all temperature channels. If the temperature channel
drops below the low limit, then the appropriate status bit is set and the ALERT# pin are asserted (if
enabled).
All Limit Registers are Software Locked.
The Fan 1 Setting Register always displays the current setting of the Fan 1 Driver. Likewise, the Fan
2 Setting Register always displays the current setting of the Fan 2 driver. Reading from either register
will report the current fan speed setting of the appropriate fan driver regardless of the operating mode.
Therefore it is possible that reading from this register will not report data that was previously written
into this register.
While the RPM based Fan Speed Control Algorithm or the Look Up Table are active (or both), then
the register is read only. Writing to the register will have no affect and the data will not be stored.
If both the RPM based Fan Control Algorithm and the Look Up Table are disabled, then the register
will be set with the previous value that was used. The register is read / write and writing to this register
will affect the fan speed.
If the Fan 2 fan driver is disabled and the DAC2 / PWM2 / GPIO2 and TACH2 / GPIO1 pins are used
as GPIOs, then the Fan 2 Setting Register will read 00h.
The contents of the register represent the weighting of each bit in determining the final output voltage.
The output drive for a PWM output is given by
is given by
Fan Setting Registers
Internal Diode
REGISTER
VIN 4 Low
Low Limit
Fan 1 Setting
Fan 2 Setting
Limit
REGISTER
as a voltage input, then the corresponding temperature high and low limit registers are
compared against the measured voltage. The data format is the same as the measured
voltage and these registers should be updated accordingly.
Equation
[3].The output drive for the High Side Fan Driver output is given by
752.9
Sign
Table 6.28 Limit Registers (continued)
B7
Table 6.29 Fan Driver Setting Register
128
128
B7
376.5
B6
64
DATASHEET
B6
64
64
188.2
B5
32
69
B5
32
32
Equation
94.12
B4
16
B4
16
16
[2]. The output drive for the Linear DAC driver
47.06
B3
B3
8
8
8
23.53
B2
4
4
B2
4
B1
2
2
11.76
B1
2
Revision 1.74 (05-08-08)
B0
1
1
5.88
B0
1
Equation
DEFAULT
00h
00h
DEFAULT
(0°C)
[4].
(0V)
00h
00h