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AS3421 AS3422

Datasheet - D e t a i l e d D e s c r i p t i o n

Figure 29. Byte Write

Figure 30. Page Write

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

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.

P

Stop condition

R

1 bit

WA++

Increment word address internally

R

during acknowledge

AS3421 AS3422 (=slave) receives data

AS3421 AS3422 (=slave) transmits data

Table 13. 2-Wire Serial Symbol Definition

Symbol

Definition

RW

Note

S

DW

A

WA

A

reg_data

A

P

write register

WA++

S

DW

A

WA

A

reg_data 1

A

P

write register

WA++

reg_data 2

A

write register

WA++

reg_data n

A

write register

WA++

...