EMC6D100-DK SMSC [SMSC Corporation], EMC6D100-DK Datasheet - Page 57

• Manufacturer Part Number: EMC6D100-DK
• Description: ENVIRONMENTAL MONITORING AND CONTROL DEVICE WITH AUTOMATIC FAN CAPABILITY
• Manufacturer: SMSC [SMSC Corporation]

REGISTER
REGISTER
Environmental Monitoring and Control Device
Datasheet
8.22
ADDRESS
8.23
ADDRESS
SMSC EMC6D100/EMC6D101
6Ch
6Ah
6Bh
67h
68h
69h
Registers 67-69h: 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.
These are the temperature limits for the individual zones. When the current temperature equals this limit,
the fan will be turned on if it is not already. When the temperature exceeds this limit, the fan speed will be
increased according to the auto fan algorithm based on the setting in the Zone x Range / FANx Frequency
register. Default = 90°C=5Ah
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 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 fan configuration registers.
This is a safety feature that attempts to cool the system if there is a potentially catastrophic thermal event.
READ/
WRITE
READ/
WRITE
R/W
R/W
R/W
R/W
R/W
R/W
Absolute Limit
Absolute Limit
Absolute Limit
Zone 1 Temp
Zone 2 Temp
Zone 3 Temp
Zone 1 Fan
Zone 2 Fan
Zone 3 Fan
Temp Limit
Temp Limit
Temp Limit
REGISTER
REGISTER
NAME
NAME
-127°c
-50°c
0°c
50°c
127°c
Table 8.13 - Temperature Limit vs. Register Setting
LIMIT
(MSB)
(MSB)
BIT 7
BIT 7
7
7
7
7
7
7
DATASHEET
-127
-50
0
50
127
BIT 6
BIT 6
LIMIT (DEC)
6
6
6
6
6
6
Page 57
BIT 5
BIT 5
5
5
5
5
5
5
BIT 4
BIT 4
4
4
4
4
4
4
81h
CEh
00h
32h
7Fh
LIMIT (HEX)
BIT 3
BIT 3
3
3
3
3
3
3
BIT 2
BIT 2
2
2
2
2
2
2
BIT 1
BIT 1
1
1
1
1
1
1
(LSB)
(LSB)
BIT 0
BIT 0
0
0
0
0
0
0
Rev. 09-09-04
DEFAULT
DEFAULT
VALUE
VALUE
5Ah
5Ah
5Ah
64h
64h
64h