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AS7221

I²C Master Interface

Datasheet

• PUBLIC

DS000479

• v4-00 • 2019-Jun-28

│ 24

8.2

I²C Write Access

Byte Write and Page Write formats are used to write data to the slave.

Figure 20:

2C Byte Write

Figure 21:

2C Page Write

The transmission begins with the START condition, which is generated by the master when the bus is

in IDLE state (the bus is free). The device-write address is followed by the word address. After the

word address any number of data bytes can be sent to the slave. The word address is incremented

internally, in order to write subsequent data bytes on subsequent address locations.

For reading data from the slave device, the master has to change the transfer direction. This can be

done either with a repeated START condition followed by the device-read address, or simply with a

new transmission START followed by the device-read address, when the bus is in IDLE state. The

device-read address is always followed by the 1st register byte transmitted from the slave. In Read

mode any number of subsequent register bytes can be read from the slave. The word address is

incremented internally.

8.3

I²C Read Access

Random, Sequential and Current Address Read are used to read data from the slave.

Figure 22:

2C Random Read

AS7221 数据表(PDF) 25 Page - OSRAM GmbH