I²C interface protocol

LNBH25

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Doc ID 022433 Rev 4

7

I²C interface protocol

7.1

Write mode transmission

The LNBH25 interface protocol comprises:

●

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 in the addressed internal register + acknowledge)

●

the following bytes, if any, to be written in successive internal registers

●

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

●

the LNBH25, as slave, acknowledges every byte transfer.

Figure 11.

ACK = Acknowledge

S = Start

P = Stop

R/W = 1/0, Read/Write bit

X = 0/1, set the values to select the CHIP ADDRESS (see Chip Address in

Table 16 for pin

selection) and to select the REGISTER Address (see

Table 7).

a.

The writing procedure can start from any Register Address by simply setting the X values in the Register

Address byte (after the Chip Address). It can be also stopped from the master by sending a stop condition after

any acknowledge bit.

AM09913v2

S

XX

00

X

00

0

X

0

0

1

0

0

0

S

XX

00

X

00

0

X

0

1

0

0

0

MSB

LSB

CHIP ADDRESS

MSB

LSB

REGISTER ADDRESS

MSB

LSB

CHIP ADDRESS

MSB

LSB

REGISTER ADDRESS

P

P

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

DATA 1

Add=0x2

DATA 2

Add=0x3

DATA 3

Add=0x4

DATA 4

Add=0x5

MSB

LSB

MSB

LSB

MSB

LSB

MSB

LSB

DATA 1

Add=0x2

DATA 2

Add=0x3

DATA 3

Add=0x4

DATA 4

Add=0x5