EMC6D103S-CZC SMSC, EMC6D103S-CZC Datasheet - Page 73

• Manufacturer Part Number: EMC6D103S-CZC
• Description: Industrial Temperature Sensors Auto Fan Contrllr Up to 4 Fans
• Manufacturer: SMSC

Specifications of EMC6D103S-CZC

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Fan Control Device with High Frequency PWM Support and Hardware Monitoring Features
Datasheet
SMSC EMC6D103
8.2.21
Register
Address
6Ah
6Bh
6Ch
Read/
Write
R/W
R/W
R/W
Registers 6A-6Ch: Absolute Temperature Limit
These registers become read only when the Lock bit is set. Any further attempts to write to these
registers shall have no effect.
In Auto Fan mode, if any zone associated with a PWM output exceeds the temperature set in the
Absolute limit register, all PWM outputs will increase their duty cycle to 100% except those that are
disabled via the PWM Configuration registers. This is a safety feature that attempts to cool the system
if there is a potentially catastrophic thermal event.
If an absolute limit register set to 80h (-128 ° c), the safety feature is disabled for the associated zone.
That is, if 80h is written into the Zone x Temp Absolute Limit Register, then regardless of the reading
register for the zone, the fans will not turn on-full based on the absolute temp condition.
Default =100 ° c=64h.
When any fan is in auto fan mode, then if the temperature in any zone exceeds absolute limit, all fans
go to full, including any in manual mode, except those that are disabled. Therefore, even if a zone is
not associated with a fan, if that zone exceeds absolute, then all fans go to full. In this case, the
absolute limit can be chosen to be 7Fh for those zones that are not associated with a fan, so that the
fans won't turn on unless the temperature hits 127 degrees.
Zone 1 Temp Absolute Limit
Zone 2 Temp Absolute Limit
Zone 3 Temp Absolute Limit
Table 8.37 Temperature Limit vs. Register Setting (continued)
ABSOLUTE LIMIT
Table 8.38 egisters 6A-6Ch: Absolute Temperature Limit
Register Name
-127 ° c
LIMIT
127 ° c
-50 ° c
50 ° c
Table 8.39 Absolute Limit vs. Register Setting
0 ° c
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ABS LIMIT (DEC)
DATASHEET
LIMIT (DEC)
(MSb)
Bit 7
7
7
7
-127
127
-50
50
0
73
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.
Bit 6
6
6
6
Bit 5
5
5
5
ABS LIMIT (HEX)
LIMIT (HEX)
Bit 4
4
4
4
CEh
7Fh
32h
81h
00h
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Bit 3
3
3
3
Bit 2
2
2
2
Bit 1
Revision 0.3 (03-01-07)
1
1
1
(LSb)
Bit 0
0
0
0
Default
Value
64h
64h
64h