Reading and writing to the STCF04 registers through the I²C bus

AN3223

22/29

Doc ID 17553 Rev 2

9

Reading and writing to the STCF04 registers through

the I²C bus

9.1

Writing to a single register

Writing to a single register starts with a START bit followed by the 7-bit device address of the

operation. Then the master awaits an acknowledgement from the STCF04. The 8-bit

address of the desired register is sent afterwards to the STCF04. It is also followed by an

acknowledge pulse. The last transmitted byte is the data which is going to be written into the

register. It is followed again by an acknowledge pulse from STCF04. Then the master

generates a STOP bit and the communication is over. See

Figure 13 below.

9.2

Writing to multiple registers with incremental addressing

It would not be practical to send the device address and the address of the register when

writing to multiple registers several times. The STCF04 supports writing to multiple registers

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

automatically incremented (by one), and therefore the next data can be sent without sending

again the device address and the register address. See

Figure 14 below.

Figure 13.

Writing to a single register

AM07807v1

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