adt7420ucpz-rl7 Analog Devices, Inc., adt7420ucpz-rl7 Datasheet - Page 16

• Manufacturer Part Number: adt7420ucpz-rl7
• Manufacturer: Analog Devices, Inc.

ADT7420
WRITING DATA
It is possible to write either a single byte of data or two bytes to
the ADT7420, depending on which registers are to be written.
Writing a single byte of data requires 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 13.
For the T
registers, it is possible to write to both the MSB and the LSB
SDA
SCL
SDA (CONTINUED)
SCL (CONTINUED)
START BY
MASTER
HIGH
SCL
SDA
START BY
MASTER
setpoint, T
1
1
0
1
1
LOW
SERIAL BUS ADDRESS BYTE
D15
1
0
setpoint, and T
0
SERIAL BUS ADDRESS BYTE
D14
FRAME 1
1
0
D13
0
FRAME 1
1
Figure 13. Writing to a Register Followed by a Single Byte of Data
D12
Figure 14. Writing to a Register Followed by Two Bytes of Data
CRIT
A1
SDA (CONTINUED)
SCL (CONTINUED)
0
DATA BYTE
FRAME 3
setpoint
D11
A0
A1
R/W
D10
A0
ADT7420
ACK. BY
Rev. PrB | Page 16 of 24
D9
9
R/W
ADT7420
ACK. BY
D8
P7
1
ADT7420
D7
ACK. BY
9
1
P6
9
D6
P7
1
registers in the same write transaction. Writing two bytes of
data to these registers requires the serial bus address, the data
register address of the MSB register written to the address
pointer register, followed by the two data bytes written to the
selected data register. This is shown in Figure 14.
If more than the required number of data bytes is written to a
register, the register ignores these extra data bytes. To write to
a different register, a start or repeated start is required.
ADDRESS POINTER REGISTER BYTE
D7
P5
1
P6
D5
ADDRESS POINTER REGISTER BYTE
P4
D6
D4
P5
FRAME 2
DATA BYTE
FRAME 3
D5
P3
P4
D3
FRAME 2
P2
D4
Preliminary Technical Data
P3
D2
DATA BYTE
FRAME 4
D3
P1
P2
D1
D2
P0
D0
P1
ADT7420
ACK. BY
ADT7420
ACK. BY
D1
9
P0
9
ADT7420
ACK. BY
D0
ADT7420
ACK. BY
9
STOP BY
MASTER
9
STOP BY
MASTER