The second (A5), third (A4), fourth (A3), sixth (A1), and

last (A0) bits of the MAX7316 slave address are always

1, 0, 0, 0, and 0. Slave address bits A6 and A2 are

selected by the address input AD0. AD0 can be con-

nected to GND, V+, SDA, or SCL. The MAX7316 has four

possible slave addresses (Table 1), and therefore a

maximum of four MAX7316 devices can be controlled

independently from the same interface.

Message Format for Writing the MAX7316

A write to the MAX7316 comprises the transmission of

the MAX7316’s slave address with the R/W bit set to

zero, followed by at least 1 byte of information. The first

byte of information is the command byte. The com-

mand byte determines which register of the MAX7316

is to be written to by the next byte, if received (Table 2).

If a STOP condition is detected after the command byte

is received, then the MAX7316 takes no further action

beyond storing the command byte.

Any bytes received after the command byte are data

bytes. The first data byte goes into the internal register

of the MAX7316 selected by the command byte (Figure

8). If multiple data bytes are transmitted before a STOP

condition is detected, these bytes are generally stored

in subsequent MAX7316 internal registers because the

command byte address autoincrements (Table 2). A

diagram of a write to the output ports registers (blink

phase 0 register or blink phase 1 register) is given in

Figure 10.

10-Port I/O Expander with LED Intensity

Control and Interrupt

_______________________________________________________________________________________

9

DEVICE ADDRESS

PIN AD0

A6

A5

A4

A3

A2

A1

A0

SCL

1

100

000

SDA

1

100

100

GND

0

100

000

V+

0

100

100

Figure 8. Command and Single Data Byte Received

SA

A

A

P

0

SLAVE ADDRESS

COMMAND BYTE

DATA BYTE

1

BYTE

AUTOINCREMENT MEMORY ADDRESS

D15 D14 D13 D12 D11 D10

D9

D8

D1

D0

D3

D2

D5

D4

D7

D6

ACKNOWLEDGE FROM MAX7316

ACKNOWLEDGE FROM MAX7316

ACKNOWLEDGE FROM MAX7316

HOW COMMAND BYTE AND DATA BYTE MAP INTO

MAX7316'S REGISTERS

R/W

Figure 9. n Data Bytes Received

SA

A

A

P

0

SLAVE ADDRESS

COMMAND BYTE

DATA BYTE

N

BYTES

AUTOINCREMENT MEMORY ADDRESS

D15 D14 D13 D12 D11 D10

D9

D8

D1

D0

D3

D2

D5

D4

D7

D6

ACKNOWLEDGE FROM MAX7316

ACKNOWLEDGE FROM MAX7316

ACKNOWLEDGE FROM MAX7316

HOW COMMAND BYTE AND DATA BYTE MAP INTO

MAX7316'S REGISTERS

R/W

Figure 7. Command Byte Received

SA

A

P

0

SLAVE ADDRESS

COMMAND BYTE

ACKNOWLEDGE FROM MAX7316

D15

D14

D13

D12

D11

D10

D9

D8

COMMAND BYTE IS STORED ON RECEIPT OF

STOP CONDITION

ACKNOWLEDGE FROM MAX7316

R/W