emc2104 Standard Microsystems Corp., emc2104 Datasheet - Page 26

• Manufacturer Part Number: emc2104
• Description: Emc2104 Dual Rpm-based Pwm Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

APPLICATION NOTE: It is important that the TACH Target settings are in the proper format when using the RPM
Revision 1.74 (05-08-08)
5.3
5.4
Fan Driver Setting
(read / write)
EDGES[1:0]
-
UPDATE[2:0]
(Fan Configuration)
LEVEL
(Spin Up
Configuration)
SPINUP_TIME[1:0]
(Spin Up
Configuration)
Fan Step
-
Valid TACH Count
-
TACH Reading
-
-
DIRECT SETTING
MODE
The EMC2104 supports two PWM output drivers. These output drivers can be configured
independently to operate as an open-drain (default) or push-pull driver and can be configured with
normal or inverse polarity. Additionally, the each PWM driver frequency is programmable with ranges
from 9.5Hz to 26kHz in four programmable frequency bands.
The EMC2104 uses a look-up table to apply a user-programmable fan control profile based on
measured temperature to each fan driver. In this look-up table, each temperature channel is allowed
PWM Fan Driver
Fan Control Look-Up Table
The TACH / DRIVE bit in the Look Up Table Configuration Register MUST be set to ‘0’ or
the TACH Target values will be incorrectly set. Setting this bit to ‘0’ ensures that the settings
will be RPM settings (Tachometer counts).
based Fan Speed Control Algorithm.
Fan Driver Setting (read
only)
EDGES[1:0]
(Fan Configuration)
RANGE[1:0]
(Fan Configuration)
UPDATE[2:0]
(Fan Configuration)
LEVEL
(Spin Up Configuration)
SPINUP_TIME[1:0]
(Spin Up Configuration)
Fan Step
Fan Minimum Drive
Valid TACH Count
TACH Target (read / write)
TACH Reading
-
DRIVE_FAIL_CNT[1:0] and
Drive Band Fail Registers
Table 5.3 Fan Controls Active for Operating Mode
FSC MODE
DATASHEET
Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown
26
TACH Reading
Fan Driver Setting (read
only)
EDGES[1:0]
-
UPDATE[2:0]
(Fan Configuration)
LEVEL
(Spin Up Configuration)
SPINUP_TIME[1:0]
(Spin Up Configuration)
Fan Step
Valid TACH Count
-
Look Up Table Drive /
Temperature Settings (read
only)
-
DIRECT SETTING W/ LUT
MODE
EDGES[1:0]
Fan Minimum Drive
Valid TACH Count
TACH Reading
Fan Driver Setting (read
only)
RANGE[1:0]
(Fan Configuration)
UPDATE[2:0]
(Fan Configuration)
LEVEL
(Spin Up Configuration)
SPINUP_TIME[1:0]
(Spin Up Configuration)
Fan Step
TACH Target (read
only)
Look up Table Drive /
Temperature Settings
(read only)
DRIVE_FAIL_CNT[1:0]
and Drive Band Fail
Registers
FSC W/ LUT MODE
SMSC EMC2104
Datasheet