Introduction

STCF03

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7.9

Interface protocol

The interface protocol is composed:

- A start condition (START)

- A Device address + R/W bit (read =1 / write =0)

- A Register address byte

- A sequence of data n* (1 byte + acknowledge)

- A stop condition (STOP)

The Register address byte determines the first register in which the read or write operation

takes place. When the read or write operation is finished, the register address is

automatically increased.

7.10

Writing to multiple registers with incremental addressing

It would be unpractical to send several times the device address and the address of the

register when writing to multiple registers. STCF03 supports writing to multiple registers with

incremental addressing. When the data is written to a register, the address register is

automatically increased, so the next data can be sent without sending the device address

and the register address again. See Figure 9 below.

Figure 8.

Writing to a single register

S

T

A

R

T

DEVICE

ADDRESS

7 bits

A

C

K

W

R

I

T

E

M

S

B

L

S

B

R

/

W

A

C

K

ADDRESS OF

REGISTER

DATA

A

C

K

A

C

K

S

T

O

P

M

S

B

M

S

B

L

S

B

L

S

B

SDA LINE

S

T

A

R

T

DEVICE

ADDRESS

7 bits

A

C

K

W

R

I

T

E

M

S

B

L

S

B

R

/

W

A

C

K

ADDRESS OF

REGISTER

DATA

A

C

K

A

C

K

S

T

O

P

M

S

B

M

S

B

L

S

B

L

S

B

S

T

A

R

T

DEVICE

ADDRESS

7 bits

A

C

K

W

R

I

T

E

M

S

B

L

S

B

R

/

W

A

C

K

ADDRESS OF

REGISTER

DATA

A

C

K

A

C

K

S

T

O

P

M

S

B

M

S

B

L

S

B

L

S

B

SDA LINE