1°C Triple Temperature Sensor with Resistance Error Correction
Datasheet
4.7
Extended Temperature Data Format Registers FAh, FBh, FCh,
FDh
For registers displaying extended temperature data format, a value of 64d is subtracted from the
Legacy Format output. This effectively extends the range to cover higher external temperature
measurements while still maintaining the 2’s complement format. Obviously, the host will have to
compensate and add 64d to the read temperature data. This format spans from –63.875ºC to
+191.875ºC with 0.125ºC resolution. Temperatures outside this range are limited to –63.875ºC and
+191.875ºC. Table 4.5 shows example temperature readings and register content for this data format.
Table 4.5 Extended Temperature Data Format
ACTUAL TEMP.
-64°C OFFSET
(°C)
2’S COMPLEMENT
(°C)
OF -64°C OFFSET
HEX
Diode Fault
= -63.875
-63
100 0000 0000
100 0000 0001
100 0000 1000
101 1111 1000
110 0000 0000
110 0000 0001
110 0000 1000
111 1111 1000
000 0000 0000
000 0000 1000
011 1111 1000
011 1111 1111
400
401
408
5F8
600
601
608
7F8
000
008
3F8
3FF
-127.875
-127
-65
-1
0
-64
+0.125
+1
-63.875
-63
+63
-1
+64
0
+65
1
+191
= +191.875
127
127.875
Table 4.4 and Table 4.5 show that temperature data is stored in 2’s complement in both Legacy and
Extended Temperature Data Format. Both extended and legacy temperature formats are updated
simultaneously after every conversion cycle. Code 400h is reserved for diode fault signaling which
occurs when open or short conditions are present between the external DP and DN pins.
4.8
Status Register
Table 4.6 Status Register
REGISTER
Status
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
DEF
Busy
-
-
-
-
-
D2
D1
00h
The Status register is a read only register and returns the operational status of the part. It indicates an
external diode fault conditions through bit 0 and 1. When either D1 or D2 is set, a faulty diode
connection is detected for external diode 1 or external diode 2 respectively. Also, when diode faults
are detected, temperature readings for the faulty external diode will return 400h. The EMC1023 detects
both open and short conditions for all diode pins. Bit 7 of the status register will be set when the
internal ADC is busy converting data.
SMSC EMC1023
Revision 1.2 (04-15-05)
DATA1S3HEET
SMSC [ SMSC CORPORATION ]
