EMC2103 Standard Microsystems Corporation, EMC2103 Datasheet - Page 63

• Manufacturer Part Number: EMC2103
• Description: Rpm-based Fan Controller with HW Thermal Shutdown
• Manufacturer: Standard Microsystems Corporation

ADDR
50h
RPM-Based Fan Controller with HW Thermal Shutdown
Datasheet
APPLICATION NOTE: When the LUT_LOCK bit is set at a logic ‘0’, the PWM drive setting will be set at whatever
SMSC EMC2103
6.32
R/W
R/W
RPM
The Look Up Table Configuration Register controls the setup information for the temperature to fan
drive look up table.
Bit 7 - USE_DTS_F1 - This bit determines whether the Pushed Temperature 1 Register is using DTS
data.
Bit 6 - USE_DTS_F2 - This bit determines whether the Pushed Temperature 2 Register is using DTS
data.
Bit 5 - LUT_LOCK - This bit locks updating the Look Up Table entries and determines whether the look
up table is being used.
Look Up Table Configuration Register
Configuration
REGISTER
‘0’ (default) - The Pushed Temperature 1 Register is not using DTS data. The contents of the
Pushed Temperature 1 registers is standard temperature data.
‘1’ - The Pushed Temperature 1 Register is loaded with DTS data. The contents of this register is
automatically subtracted from a fixed value of 100°C before being compared to the Look Up Table
threshold levels.
‘0’ (default) - The Pushed Temperature 2 Register is not using DTS data. The contents of this
register is standard 2’s complement temperature data.
‘1’ - The Pushed Temperature 2 Register is loaded with DTS data. The contents of this register is
automatically subtracted from a fixed value of 100°C before being compared to the Look Up Table
threshold levels.
‘0’ (default) - The Look Up Table entries can be updated normally. The Look Up Table will not be
used while the Look Up Table entries are unlocked. During this condition, the PWM output will not
change states regardless of temperature or tachometer variation.
‘1’ - The Look Up Table entries are locked and cannot be updated. The Look Up Table is fully active
and will be used based on the loaded values. The PWM output will be updated depending on the
temperature and / or TACH variations.
=
LUT
------------------- -
(
poles
RPM
value was last used by the RPM based Fan Speed Control Algorithm or the Look Up Table.
1
)
=
×
--------------------------------- -
COUNT
3,932,160 m
------------------------------------- -
USE_D
Table 6.48 Look Up Table Configuration Register
TS_F1
B7
(
COUNT
n 1
–
)
×
---- -
m
×
1
USE_D
TS_F2
×
B6
1,966,080
DATASHEET
LUT_L
OCK
B5
63
RPM /
PWM
B4
poles = number of poles of the fan
COUNT = TACH Reading Register
m = the multiplier defined by the
n = number of edges measured
B3
-
value (in decimal)
TEMP3
_CFG
RANGE bits
B2
(typically 2)
(typically 5)
where:
B1
-
Revision 0.85 (01-29-08)
TEMP4
_CFG
B0
DEFAULT
[3]
[4]
00h