2-Wire-Interfaced, 2.5V to 5.5V, 20-Port or

28-Port I/O Expander

12

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COMMAND BYTE ADDRESS RANGE

AUTOINCREMENT BEHAVIOR

x0000000 to x1111110

Command address autoincrements after byte read or written

x1111111

Command address remains at x1111111 after byte written or read

PIN

CONNECTION

DEVICE ADDRESS

AD1

AD0

A6

A5

A4

A3

A2

A1

A0

GND

GND

1

0

0

0

0

0

0

GND

V+

100

000

1

GND

SDA

100

001

0

GND

SCL

100

001

1

V+

GND

100

010

0

V+

V+

100

010

1

V+

SDA

100

011

0

V+

SCL

100

011

1

SDA

GND

100

100

0

SDA

V+

100

100

1

SDA

SDA

1

0

0

1

0

1

0

SDA

SCL

1

0

0

1

0

1

1

SCL

GND

100

110

0

SCL

V+

100

110

1

SCL

SDA

1

0

0

1

1

1

0

SCL

SCL

1

0

0

1

1

1

1

SA

A

A

P

0

SLAVE ADDRESS

COMMAND BYTE

DATA BYTE

ACKNOWLEDGE FROM MAX7300

D15 D14 D13 D12 D11 D10

D9

D8

D1

D0

D3

D2

D5

D4

D7

D6

HOW COMMAND BYTE AND DATA BYTE MAP INTO MAX7300’s REGISTER

ACKNOWLEDGE FROM MAX7300

R/W

‘n’ BYTES

AUTOINCREMENT MEMORY WORD ADDRESS

ACKNOWLEDGE FROM MAX7300

Figure 9. ‘n’ Data Bytes Received

Table 3. MAX7300 Address Map

Table 4. Autoincrement Rules