Datasheet
ADT75 Data Sheet
Rev. B | Page 18 of 24
05326-015
FRAME 1
SERIAL BUS ADDRESS BYTE
FRAME 2
ADDRESS POINTER REGISTER BYTE
ACK. BY
ADT75
ACK. BY
ADT75
ACK. BY
ADT75
STOP BY
MASTER
FRAME 4
DATA BYTE
SCL
SDA
START BY
MASTER
1 0 0 1 A2 A1 A0 P7 P6 P5 P4 P3 P2 P1 P0
9
D7 D6 D5 D4 D3 D2 D1 D0
R/W
191
91
ACK. BY
ADT75
FRAME 3
DATA BYTE
SDA (CONTINUED)
SCL (CONTINUED)
D15 D14 D13 D12 D11 D10 D9 D8
91
Figure 16. Writing to the Address Pointer Register Followed by Two Bytes of Data to Either T
HYST
or T
OS
Registers
SCL
SDA
1
1 0 0 1 A2A1 A0
START BY
MASTER
FRAME 1
SERIAL BUS ADDRESS
BYTE
FRAME 2
DATA BYTE FROM CONFIGURATION
REGISTER
STOP BY
MASTER
ACK. BY
ADT75
NO ACK. BY
MASTER
R/W D7 D6 D5 D4 D3 D2 D1 D0
9
91
05326-016
Figure 17. Reading Back Data from the Configuration Register
FRAME 1
SERIAL BUS ADDRESS BYTE
FRAME 2
MSB DATA BYTE FROM TEMPERATURE
VALUE REGISTER
ACK. BY
ADT75
ACK. BY
MASTER
SCL
SDA
START BY
MASTER
1 0 0 1 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8
9
R/W
191
05326-017
NO ACK. BY
MASTER
STOP BY
MASTER
FRAME 3
LSB DATA BYTE FROM TEMPERATURE
VALUE REGISTER
SDA (CONTINUED)
SCL (CONTINUED)
D7 D6 D5 D4 D3 D2 D1 D0
91
Figure 18. Reading Back Data from the Temperature Value Register
READING DATA
Reading data from the ADT75 is done in a one data byte operation
for the configuration register and a two data byte operation for
the temperature value register, T
HYST
register, and the T
OS
setpoint
register. Reading back the contents of the configuration register
is shown in Figure 17. Reading back the contents of the temperature
value register is shown in Figure 18. Reading back from any register
first requires a single-byte write operation to the address pointer
register to set up the register address of the register that is going
to be read from. To read from another register, execute another
write to the address pointer register to set up the relevant register
address. Thus, block reads are not possible, that is, there is no I
2
C
auto-increment. If the address pointer register has previously been
set up with the address of the register that is going to receive a
read command then there is no need to repeat a write operation
to set up the register address again.