Data Sheet

MLX90393

Micropower Triaxis® Magnetometer Datasheet

• Transmitting the Status Byte by the Slave, who is in control of the bus. Following the RR and RM

commands the sensor returns additional data bytes after the status byte.

• Acknowledging by the Master if the data is well received

• Generating a Stop condition (P) by the master

The Master controlled bus activity is shown in blue, the Slave controlled bus activity is shown in orange. In

case a command is longer than a single byte (see Table 6), the bytes are transmitted sequentially before

generating the Start Repeat (Sr) condition.

I2C_ADDR[6:0] W

ACK

COMMAND[7:0]

ACK

I2C_ADDR[6:0] R

ACK

STATUS_BYTE[7:0]

ACK

SCL

SDA

SCL

SDA

1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9

Figure 6: Default I2C communication example with status byte readback

The same applies to the Slave responses: following RR and RM commands, the Slave response is more than

just the Status Byte. There as well, the data is partitioned in bytes that are transmitted sequentially by the

slave. It is the Master’s responsibility to issue enough clocking pulses to read back all the data. Finding out

how many bytes is possible by decoding the Status Byte information, see Section Status Byte.

Finally the master is also free to not read back the status byte when issuing a command. In doing so, he

loses the ability to see if the command was received properly by the MLX90393. Moreover, the first SM

command issued by the master after power-up or reset should have the status byte read back in order to

get valid measurement data back.

3901090393 Data Sheet

Rev002 Page 16 Feb-2015