Philips Semiconductors

Product data sheet

LM75A

Digital temperature sensor and thermal Watchdog

™

2004 Oct 05

13

Protocols for writing and reading the registers

SL01393

123456789

1234

56789123456789

1001

A2

A1

A0

1

W

A

0000

000

S

D4

D3

D2

D1

A

000

A

P

D0

DEVICE ADDRESS

POINTER BYTE

SCL

SDA

CONFIGURATION DATA BYTE

START

WRITE

DEVICE

ACKNOWLEDGE

DEVICE

ACKNOWLEDGE

STOP

DEVICE

ACKNOWLEDGE

Figure 6. Write configuration register (1-byte data).

SL01398

123456789

1001

A2

A1

A0

R

A

DEVICE ADDRESS

SCL (cont.)

SDA (cont.)

READ

DEVICE

ACKNOWLEDGE

D4

D3

D2

D1

D0

D7

D6

D5

1234

56789

P

MASTER NOT

ACKNOWLEDGED

STOP

NA

DATA BYTE FROM DEVICE

123456789

1234

56789

1001

A2

A1

A0

1

W

A

0000

000

S

A

DEVICE ADDRESS

POINTER BYTE

SCL

SDA

START

WRITE

DEVICE

ACKNOWLEDGE

DEVICE

ACKNOWLEDGE

0

RE-START

RS

(next)

(next)

Figure 7. Read configuration register including Pointer byte (1-byte data).

SL01394

123456789

1234

56789

1001

A2

A1

A0

R

A

S

D4

D3

D2

D1

NA

P

D0

DEVICE ADDRESS

SCL

SDA

DATA BYTE FROM DEVICE

START

READ

DEVICE

ACKNOWLEDGE

MASTER NOT

ACKNOWLEDGED

STOP

D7

D6

D5

Figure 8. Read configuration register with preset Pointer (1-byte data).