Preliminary Technical Data

AD5625R/AD5645R/AD5665R, AD5625/AD5665

Rev. PrA. | Page 23 of 32

R/W

0

SCL

SDA

0

0

1

1

A1

A0

DB23 DB 22 D B21 DB 20 DB1 9 DB 18 D B17 DB 16

ACK. BY

MASTER

START BY

MASTER

FRAME 1

SLAVE ADDRESS

FRAME 2

COMMAND BYTE

19

1

ACK. BY

AD56x5

9

DB7

D B 6

DB 5

D B4

D B3

DB 2

D B1

DB 0

NO ACK.

STOP BY

MASTER

19

9

SCL

(CONTINUED)

SDA

(CONTINUED)

DB15 DB14 D B13 DB12 DB11 DB1 0 DB9

DB8

ACK. BY

MASTER

1

FRAME 3

MOST SIGNIFICANT

DATA BYTE

FRAME 4

LEAST SIGNIFICANT

DATA BYTE

R/W

0

SCL

SDA

0

1

A1

A0

DB23 DB 22 DB2 1 DB20 DB 19 DB1 8 DB1 7 DB 16

ACK. BY

MASTER

START BY

MASTER

FRAME 1

SLAVE ADDRESS

FRAME 2

COMMAND BYTE

19

1

ACK. BY

AD56x5

9

DB 7

D B 6

DB5

DB4

DB3

DB 2

DB1

DB0

NO ACK.

STOP BY

MASTER

19

9

SCL

(CONTINUED)

SDA

(CONTINUED)

DB15 D B14 DB 13 DB 12 DB1 1 DB1 0 D B9

DB8

ACK. BY

MASTER

1

FRAME 3

MOST SIGNIFICANT

DATA BYTE

FRAME 4

LEAST SIGNIFICANT

DATA BYTE

A3

A2

HIGH SPEED MODE

Some models offer high-speed serial communication with a

clock frequency of 3.4 MHz. See the Ordering Information on

the back page for a full list of models.

High speed mode communication commences after the master

addresses all devices connected to the bus with the Master Code

00001XXX to indicate that a high speed mode transfer is to

begin. No device connected to the bus is permitted to

acknowledge the high speed master code, therefore, the code is

followed by a no acknowledge. The master must then issue a

repeated start followed by the device address. The selected

device then acknowledges its address. All devices continue to

operate in high speed mode until the master issues a stop

condition. When the stop condition is issued, the devices

return to standard/fast mode. The part will also exit high speed

mode if

0

SCL

SDA

0

0

1

X

X

0

0

0

1

1

A1

A0

START BY

MASTER

HS-MODE MASTER CODE

SERIAL BUS ADDRESS BYTE*

19

1

9

ACK. BY

AD56x5

0

X

NACK

SR

R/W

FAST MODE

HIGH-SPEED MODE

*NOTE: ADDRESS SHOWN IS FOR 10-PIN DEVICE. ADDRESS FOR 14-PIN DEVICE IS 001(A3)(A2)(A1)(A0)

Figure 56. Placing the AD56x5 in High-Speed Mode