AK9752AE Datasheet, PDF (18/36 Pages) Asahi Kasei Microsystems – Ultra-small IR sensor IC with IC

[AK9752]
11.1.4. Slave Address
The slave address of the AK9752 is fixed to 64H.
When the first one byte data including the slave address is transmitted after a Start Condition, the
device, which is specified as the communicator by the slave address on bus, is selected.
After transmitting the slave address, the device that has the corresponding device address will execute a
command after transmitting an Acknowledge signal. The 8-bit (Least Significant bit-LSB) of the first one
byte is the R/W bit.
When the R/W bit is set to “1”, a read command is executed. When the R/W bit is set to “0”, a write
command is executed.
MSB
1
1
0
0
1
0
Figure 11.4. Slave Address
LSB
0 R/W
11.1.5. Write Command
When the R/W bit set to “0”, the AK9752 executes a write operation. The AK9752 will output an
Acknowledge signal and receive the second byte, after receiving a Start Condition and first one byte
(slave address) in a write operation. The second byte has an MSB-first configuration, and specifies the
address of the internal control register.
MSB
LSB
A7 A6 A5 A4 A3 A2 A1 A0
Figure 11.5. Register Address
The AK9752 will generate an Acknowledge and receive the third byte after receiving the second byte
(Register Address).
The data after the third byte are the control data. The control data consists of 8-bit and has an MSB-first
configuration. The AK9752 generates an Acknowledge for each byte received. The data transfer is
terminated by a Stop Condition, generated by the master device.
MSB
LSB
D7 D6 D5 D4 D3 D2 D1 D0
Figure11.6. Control data
Two or more bytes can be written at once. The AK9752 generates an Acknowledge and receives the
next data after receiving the third byte (Control Data). When the following data is transmitted without a
Stop Condition, after transmitting one byte, the internal address counter is automatically incremented,
and data is written in the next address.
The automatic address increment works for the registers which set threshold of IR, threshold of
Temperature Sensor, interrupt source, cut-off frequency of digital filter, and operation mode (0BH~15H).
The address counter returns to address 0BH after reaching address 15H.
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