MAX7314 Maxim, MAX7314 Datasheet - Page 9

• Manufacturer Part Number: MAX7314
• Description: The MAX7314 I²C-compatible serial interfaced peripheral provides microprocessors with 16 I/O ports plus one output-only port and one input-only port
• Manufacturer: Maxim

The second (A5), third (A4), fourth (A3), sixth (A1), and
last (A0) bits of the MAX7314 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 MAX7314 has four
possible slave addresses (Table 1), and therefore a
maximum of four MAX7314 devices can be controlled
independently from the same interface.
Table 1. MAX7314 Address Map
Figure 7. Command Byte Received
Figure 8. Command and Single Data Byte Received
Figure 9. n Data Bytes Received
PIN AD0
GND
SDA
SCL
V+
S
S
HOW COMMAND BYTE AND DATA BYTE MAP INTO
HOW COMMAND BYTE AND DATA BYTE MAP INTO
A6
1
1
0
0
S
ACKNOWLEDGE FROM MAX7314
SLAVE ADDRESS
ACKNOWLEDGE FROM MAX7314
SLAVE ADDRESS
18-Port GPIO with LED Intensity Control,
A5
_______________________________________________________________________________________
1
1
1
1
Interrupt, and Hot-Insertion Protection
MAX7314's REGISTERS
MAX7314's REGISTERS
DEVICE ADDRESS
A4
COMMAND BYTE IS STORED ON RECEIPT OF
0
0
0
0
SLAVE ADDRESS
R/W
R/W
A3
0
0
0
0
ACKNOWLEDGE FROM MAX7314
0
0
A2
A
A
0
1
0
1
D15 D14 D13 D12 D11 D10
D15 D14 D13 D12 D11 D10
STOP CONDITION
A1
R/W
0
0
0
0
0
ACKNOWLEDGE FROM MAX7314
ACKNOWLEDGE FROM MAX7314
COMMAND BYTE
COMMAND BYTE
A0
0
0
0
0
A
D15
A write to the MAX7314 comprises the transmission of
the MAX7314’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 MAX7314
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 MAX7314 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 MAX7314 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 MAX7314 internal registers because the
command byte address autoincrements (Table 2). A
diagram of a write to the output ports registers (blink
phase 0 registers or blink phase 1 registers) is given in
Figure 10.
D14
D9
D9
D8
D8
D13
COMMAND BYTE
Message Format for Writing the MAX7314
A
A
D12
ACKNOWLEDGE FROM MAX7314
D7
D7
D11
AUTOINCREMENT MEMORY ADDRESS
AUTOINCREMENT MEMORY ADDRESS
D6
D6
D10
D5
D5
ACKNOWLEDGE FROM MAX7314
ACKNOWLEDGE FROM MAX7314
DATA BYTE
DATA BYTE
D4
D4
D9
BYTES
BYTE
N
1
D3
D3
D8
D2
D2
A
D1
D1
P
D0
D0
A
A
P
P
9