emc2106 Standard Microsystems Corp., emc2106 Datasheet - Page 70

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

ADDR
ADDR
41h
81h
Revision 1.74 (05-08-08)
42h
82h
6.24
6.25
R/W
R/W
R/W
R/W
R/W
R/W
The PWM 1 and 2 Divide Registers determine the final frequency of the PWM 1and PWM 2 drivers.
Each driver base frequency is divided by the value of the respective PWM Divide Register to determine
the final frequency. The duty cycle settings are not affected by these settings, only the final frequency
of the PWM driver. A value of 00h will be decoded as 01h.
The Fan Configuration 1 Register controls the general operation of the RPM based Fan Speed Control
Algorithm used for the Fan 1 driver.
Bit 7 - EN_ALGO - enables the RPM based Fan Speed Control Algorithm. This bit is set and cleared
automatically when the LUT_LOCK bit is set based on the setting of the TACH / DRIVE bit (see
Section
using the Look Up Table.
PWM 1 and 2 Divide Registers
Fan Configuration 1 Registers
‘0’ - (default) the control circuitry is disabled and the fan driver output is determined by the Fan
Driver Setting Register.
‘1’ - the control circuitry is enabled and the Fan Driver output will be automatically updated to
maintain the programmed fan speed as indicated by the TACH Target Register.
PWM 1 Divide
PWM 2 Divide
REGISTER
Configuration
Configuration
6.35). When the LUT_LOCK bit is cleared, then setting this bit will enable the FSC without
REGISTER
Fan 1
Fan 2
1
1
Drive
Drive
Drive
Table 6.30 PWM 1 and 2 Divide Registers
Table 6.31 Fan Configuration 1 Registers
=
=
128
128
=
B7
ALGO
ALGO
EN_
EN_
⎛
⎝
⎛
⎝
B7
⎛
⎝
VALUE
-------------------- -
VALUE
-------------------- -
VALUE
-------------------- -
255
255
255
B6
64
64
DATASHEET
⎞
⎠
⎞
⎠
RANGE[1:0]
RANGE[1:0]
⎞
⎠
B6
Dual RPM-Based Linear Fan Controller with Hardware Thermal Shutdown
×
×
×
VDD
VDD_5V
100%
B5
32
32
70
B5
B4
16
16
EDGES[1:0]
EDGES[1:0]
B4
B3
8
8
B3
B2
4
4
B2
UPDATE[2:0]
UPDATE[2:0]
B1
B1
2
2
[2]
[3]
[4]
B0
B0
1
1
SMSC EMC2106
Datasheet
DEFAULT
DEFAULT
2Bh
2Bh
01h
01h