ADT75 Analog Devices, Inc., ADT75 Datasheet - Page 17

• Manufacturer Part Number: ADT75
• Description: ?1?c Accurate, 12-bit Digital Temperature Sensor
• Manufacturer: Analog Devices, Inc.

WRITING DATA
Depending on the register being written to, there are two
different writes for the ADT75.
Writing to the Address Pointer Register for a
Subsequent Read
In order to read data from a particular register, the address
pointer register must contain the address of that register. If it
does not, the correct address must be written to the address
pointer register by performing a single-byte write operation, as
shown in Figure 14. The write operation consists of the serial
bus address followed by the address pointer byte. No data is
written to any of the data registers. A read operation is then
performed to read the register.
SDA
SCL
START BY
MASTER
SDA
SCL
START BY
MASTER
1
1
Figure 15. Writing to the Address Pointer Register Followed by a Single Byte of Data to the Configuration Register
1
1
0
Figure 14. Writing to the Address Pointer Register to Select a Register for a Subsequent Read Operation
0
0
SERIAL BUS ADDRESS
SERIAL BUS ADDRESS BYTE
0
1
FRAME 1
BYTE
FRAME 1
1
A1
SDA (CONTINUED)
SCL (CONTINUED)
A2
A2
A1
A0
A0
R/W
ACK. BY
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R/W
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ACK. BY
ADT75
9
D7
9
1
P7
1
D6
P7
1
Writing Data to a Register
The configuration register is 8-bits wide so only one byte of data
can be written to this register. Writing a single byte of data to
the configuration register consists of the serial bus address, the
data register address written to the address pointer register,
followed by the data byte written to the selected data register.
This is shown in Figure 15. The T
register are each 16-bits wide, so two data bytes can be written
into these registers. Writing two bytes of data to either one of
these registers consists of the serial bus address, the data register
address written to the address pointer register, followed by the
two data bytes written to the selected data register. This is
shown in Figure 16. If more than the required number of data
bytes is written to a register then the register ignores these extra
data bytes. To write to a different register, another start or
repeated start is required.
P6
P6
D5
ADDRESS POINTER REGISTER BYTE
P5
ADDRESS POINTER REGISTER BYTE
P5
D4
P4
DATA BYTE
FRAME 3
FRAME 2
P4
D3
P3
FRAME 2
D2
P3
P2
P2
D1
P1
D0
P1
HYST
P0
ACK. BY
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P0
9
ACK. BY
register and the T
ADT75
9
ACK. BY
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9
STOP BY
MASTER
STOP BY
MASTER
ADT75
OS