PCA9675_1

© NXP B.V. 2007. All rights reserved.

Product data sheet

Rev. 01 — 1 February 2007

11 of 34

NXP Semiconductors

PCA9675

Remark: The reading of the Device ID can be stopped anytime by sending a NACK

command.

Remark: If the master continues to ACK the bytes after the third byte, the PCA9675

rolls back to the first byte and keeps sending the Device ID sequence until a NACK

has been detected.

For the PCA9675, the Device ID is as shown in Figure 13.

Fig 13. PCA9675 ID

If more than 2 bytes are read, the slave device loops back to the first byte (manufacturer byte)

and keeps sending data until the master generates a ‘no acknowledge’.

Fig 14. Device ID field reading

0

002aab639

0

0

revision

0

0

1

0

0

1

1

0

0

part identification

0

0

0

0

0

0

0

0

0

0

0

0

manufacturer

category identification

feature identification

002aab663

1

1

1

1

0

0

0

A

S

1

device ID address

START condition

R/W

acknowledge from one

or several slave(s)

A5 A4 A3 A2 A1 A0 X

A6

A

1

1

1

1

0

0

1

1

device ID address

A

the device to be identified

don't care

acknowledge from

slave to be identified

acknowledge from

slave to be identified

R/W

M6 M5 M4

M7

M2 M1 M0

M3

A

acknowledge

from master

C5 C4 C3

C6

C1 C0 F5

C2

A

acknowledge

from master

manufacturer name

= 00000000

P3 P2 P1

F4

P0 R2 R1 R0

revision = 000

feature identification

= 001100

A

P

STOP

condition

no acknowledge

from master

category identification

= 0000001