Fan Control Device with Hardware Monitoring and Acoustic Noise Reduction Features
Datasheet
There are Remote Diode (1 or 2) Fault status bits in Interrupt Status Register 2 (42h), which, when
one, indicate a short or open-circuit on remote thermal diode inputs (Remote x+ and Remote x-).
Before a remote diode conversion is updated, the status of the remote diode is checked. In the case
of a short or open-circuit on the remote thermal diode inputs, the value in the corresponding reading
register will be forced to 80h. Note that this will cause the associated remote diode limit exceeded
status bit to be set (i.e. Remote Diode x Limit Error bits (D1 and D2) are located in the Interrupt Status
1 Register at register address 41h).
The temperature change is computed by measuring the change in Vbe at two different operating points
of the diode to which the Remote x+ and Remote x- pins are connected. But accuracy of the
measurement also depends on non-ideality factor of the process the diode is manufactured on.
5.9.3
Temperature Data Format
Temperature data can be read from the three temperature registers:
■
■
■
Internal Temp Reading register (26h)
Remote Diode 1 Temp Reading register (25h)
Remote Diode 2 Temp Reading register (27h)
The following table shows several examples of the format of the temperature digital data, represented
0
by an 8-bit, two’s complement word with an LSB equal to 1.0 C.
Table 5.6 Temperature Data Format
TEMPERATURE
READING (DEC)
READING (HEX)
DIGITAL OUTPUT
-1270C
-127
81h
1000 0001
0
-50 C
-50
-25
CEh
E7h
1100 1110
1110 0111
0
-25 C
0
-1 C
-1
0
FFh
00h
01h
1111 1111
0000 0000
0000 0001
0
0 C
0
+1 C
1
0
+25 C
25
50
19h
32h
0001 1001
0011 0010
+500C
+1270C
127
128
7Fh
80h
0111 1111
1000 0000
SENSOR ERROR
Revision 0.4 (04-05-05)
SMSC EMC6D102
DATA2S6HEET
SMSC [ SMSC CORPORATION ]
