Reading and writing to the STCF03 registers through the I2C bus

AN2507

22/31

7

Reading and writing to the STCF03 registers through

7.1

Writing to a single register

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

STCF03. The 8-th bit is the R/W bit, which is 0 in this case. R/W = 1 means a Reading

operation. Then the master awaits an acknowledgement from STCF03. The 8-bit address of

the desired register is sent afterwards to STCF03. It will also be followed by an acknowledge

pulse. The last transmitted byte is the data that is going to be written into the register. It is

followed again by an acknowledge pulse from STCF03. Then the master generates a STOP-

bit and the communication is over. See Figure 17 below.

Figure 17.

Writing to a single register

7.2

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 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 18 below.

Figure 18.

Writing to multiple registers

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 i

DATA i

A

C

K

A

C

K

S

T

O

P

M

S

B

M

S

B

L

S

B

L

S

B

DATA i+1

A

C

K

L

S

B

DATA i+2

A

C

K

L

S

B

DATA i+2

L

S

B

DATA i+n

A

C

K

M

S

B

M

S

B

M

S

B

M

S

B

M

S

B

A

C

K

L

S

B

SDA LINE