TMP401
SBOS371A AUGUST 2006 REVISED OCTOBER 2007
www.ti.com
8
Table 2. Decimal Fraction Temperature Data Format (Local and Remote Temperature Low Bytes)
REMOTE
TEMPERATURE
REGISTER
LOW BYTE VALUE
LOCAL
TEMPERATURE
REGISTER
LOW BYTE VALUE
0.06255C RESOLUTION
0.55C RESOLUTION
0.255C RESOLUTION
0.1255C RESOLUTION
0.06255C RESOLUTION
TEMP
(5C)
STANDARD
AND
EXTENDED
BINARY
HEX
STANDARD
AND
EXTENDED
BINARY
HEX
STANDARD
AND
EXTENDED
BINARY
HEX
STANDARD
AND
EXTENDED
BINARY
HEX
STANDARD
AND
EXTENDED
BINARY
HEX
0.0000
0000 0000
00
0000 0000
00
0000 0000
00
0000 0000
00
0000 0000
00
0.0625
0001 0000
10
0000 0000
00
0000 0000
00
0000 0000
00
0001 0000
10
0.1250
0010 0000
20
0000 0000
00
0000 0000
00
0010 0000
20
0010 0000
20
0.1875
0011 0000
30
0000 0000
00
0000 0000
00
0010 0000
20
0011 0000
30
0.2500
0100 0000
40
0000 0000
00
0100 0000
40
0100 0000
40
0100 0000
40
0.3125
0101 0000
50
0000 0000
00
0100 0000
40
0100 0000
40
0101 0000
50
0.3750
0110 0000
60
0000 0000
00
0100 0000
40
0110 0000
60
0110 0000
60
0.4375
0111 0000
70
0000 0000
00
0100 0000
40
0110 0000
60
0111 0000
70
0.5000
1000 0000
80
1000 0000
80
1000 0000
80
1000 0000
80
1000 0000
80
0.5625
1001 0000
90
1000 0000
80
1000 0000
80
1000 0000
80
1001 0000
90
0.6250
1010 0000
A0
1000 0000
80
1000 0000
80
1010 0000
A0
1010 0000
A0
0.6875
1011 0000
B0
1000 0000
80
1000 0000
80
1010 0000
A0
1011 0000
B0
0.7500
1100 0000
C0
1000 0000
80
1100 0000
C0
1100 0000
C0
1100 0000
C0
0.8125
1101 0000
D0
1000 0000
80
1100 0000
C0
1100 0000
C0
1101 0000
D0
0.8750
1110 0000
E0
1000 0000
80
1100 0000
C0
1110 0000
E0
1110 0000
E0
0.9375
1111 0000
F0
1000 0000
80
1100 0000
C0
1110 0000
E0
1111 0000
F0
REGISTER INFORMATION
The TMP401 contains multiple registers for holding
configuration information, temperature measurement
results,   temperature   comparator   limits,   and   status
information. These registers are described in Figure 12
and Table 3.
POINTER REGISTER
Figure 12 shows the internal register structure of the
TMP401. The 8-bit Pointer Register is used to address a
given data register. The Pointer Register identifies which
of the data registers should respond to a read or write
command on the Two-Wire bus. This register is set with
every write command. A write command must be issued
to set the proper value in the Pointer Register before
executing a read command. Table 3 describes the pointer
address of the registers available in the TMP401. The
power-on reset (POR) value of the Pointer Register is 00h
(0000 0000b).
Hysteresis Register
Resolution Register
Configuration Register
Status Register
Consecutive Alert Register
OneShot Register
Identification Registers
Conversion Rate Register
Local and Remote Limit Registers
Local and Remote Temperature Registers
SDA
SCL
Pointer Register
I/O
Control
Interface
Figure 12. Internal Register Structure