I²C interface protocol

LNBH30

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DocID023739 Rev 2

7

I²C interface protocol

7.1

Write mode transmission

The LNBH30 interface protocol is made up of:



a start condition (S)



a chip address byte with the LSB bit R/W = 0



a register address (internal address of the first register to be accessed)



a sequence of data (byte to write to the addressed internal register + acknowledge)



a stop condition (P). The transfer lasts until a stop bit is encountered



the LNBH30, as slave, acknowledges every byte transfer

Figure 7: Example of writing procedure starting with first data address 0x1

ACK = acknowledge

S = start

P = stop

R/W = 1/0, read/write bit

X = 0/1, set the values to select the chip address

Only one data register address 0x1 is available for the writing procedure.

7.2

Read mode transmission

In read mode the byte sequence must be as follows:



a start condition (S)



a chip address byte with the LSB bit R/W=0



the register address byte of the internal first register to be accessed



a stop condition (P)



a new master transmission with the chip address byte and the LSB bit R/W=1



after the acknowledge the LNBH30 starts sending the addressed register content. As

long as the master keeps the acknowledge LOW, the LNBH30 transmits the next

address register byte content



the transmission is terminated when the master sets the acknowledge HIGH with a

following stop bit