2–25

This register holds the device address and the read/write command bit.

7

6

5

4

3

210

A6

A5

A4

A3

A2

A1

A0

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

BIT

NAME

RESET

FUNCTION

0

R/W

0

Read/write command bit.

R/W = 0

Write operation

R/W = 1

Read operation

7–1

A[6:0]

0000000

Seven address bits for device addressing

This register holds the received data from an external device.

7

6

5

4

3

210

D7

D6

D5

D4

D3

D2

D1

D0

R/O

R/O

R/O

R/O

R/O

R/O

R/O

R/O

BIT

NAME

RESET

FUNCTION

7–0

D[7:0]

0

8-bit input data from an I2C device

This register holds the data to be transmitted to an external device. Writing to this register starts the transfer on the

SDA line.

7

6

5

4

3

210

D7

D6

D5

D4

D3

D2

D1

D0

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

BIT

NAME

RESET

FUNCTION

7–0

D[7:0]

0

8-bit output data to an I2C device

2.11 Read/Write Operations

2.11.1 Read Operation (Serial EEPROM)

A serial read requires a dummy byte write sequence to load in the 16-bit data word address. Once the device address

word and data word are clocked out and acknowledged by the device, the MCU starts a current address sequence.

The following describes the sequence of events to accomplish this transaction:

Device Address + EEPROM [High-byte]

•

content ofthe I2CDAI register is received.

•

the content of the I2CDAO register is transmitted.

•

The MCU writes the device address (R/W bit = 0) to the I2CADR register (write operation).

•

The MCU writes the high byte of the EEPROM address into the I2CDAO register, starting the transfer on

the SDA line.