TMP122-EP_1 Datasheet, PDF (6/17 Pages) Texas Instruments – 1.5°C ACCURATE PROGRAMMABLE DIGITAL TEMPERATURE SENSORS WITH SPI™ INTERFACE

TMP122-EP
SBOS454 – NOVEMBER 2008 .......................................................................................................................................................................................... www.ti.com
Multiple commands may be strung together as illustrated in Figure 2. The TMP122 accepts commands
alternating with 16-bit response data. On lowering CS, the part always responds with a READ from the address
location indicated by the READ address register. If the next command is a READ command then data is returned
from the address specified by the READ command with the 16th clock resetting the READ address register to
the default temperature register. The TMP122 then expects a 16-bit command. If the command is a WRITE
command, then the 16 clocks following the command will again return temperature data.
Figure 3, Figure 4, Figure 5, and Figure 6 detail the communication sequences.
Table 1. READ Command
READ Command D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Temperature
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Configuration
register
1
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
Low temperature
threshold
1
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
High temperature
threshold
1
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
Table 2. WRITE Command
WRITE Command D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Temperature
0
0
0
0
D1
D0 R1 R0 F1 F0 POL TM1 TM0 0
1
0
Low temperature
threshold
T12 T11 T10 T9
T8
T7 T6 T5 T4 T3 T2 T1 T0 1
0
0
High temperature
threshold
T12 T11 T10 T9
T8
T7 T6 T5 T4 T3 T2 T1 T0 1
1
0
Shutdown command x
x
x
x
x
x
x
x
1
1
1
1
1
1
1
1
Figure 3. READ followed by WRITE Command to T_LOW/T_HIGH Register
Figure 4. READ followed by WRITE Command to Configuration Register
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