MAX7324 Maxim, MAX7324 Datasheet - Page 14

• Manufacturer Part Number: MAX7324
• Description: The MAX7324 2-wire serial-interfaced peripheral features 16 I/O ports that are divided into eight push-pull outputs and eight inputs
• Manufacturer: Maxim

I
and Eight Inputs
A write to the input ports of the MAX7324 starts with the
master transmitting the group’s slave address with the
R/W bit set low. The MAX7324 acknowledges the slave
address and samples the ports during the acknowl-
edge bit. INT deasserts during the slave acknowledge.
The master can now transmit one or more bytes of
data. The MAX7324 acknowledges these subsequent
bytes of data and updates the interrupt mask register
with each new byte until the master issues a STOP con-
dition (Figure 9).
Figure 9. Writing to the Input Ports of the MAX7324
Figure 10. Writing to the Output Ports of the MAX7324
14
2
C Port Expander with Eight Push-Pull Outputs
______________________________________________________________________________________
FROM PORT
DATA OUT
TO PORT
WRITE
SDA
SCL
SDA
SCL
START CONDITION
START CONDITION
S
S
1
1
2
2
SLAVE ADDRESS
SLAVE ADDRESS
3
3
4
4
Writing to the MAX7324
5
5
6
6
7
7
R/W
8
0
R/W
0
8
A
ACKNOWLEDGE
FROM SLAVE
A
DATA TO INTERRUPT MASK
DATA TO PORT
DATA 1
DATA 1
A write to the output ports of the MAX7324 starts with
the master transmitting the group’s slave address with
the R/W bit set low. The MAX7324 acknowledges the
slave address and samples the ports during the
acknowledge bit. The master can now transmit one or
more bytes of data. The MAX7324 acknowledges these
subsequent bytes of data and updates the correspond-
ing group’s ports with each new byte until the master
issues a STOP condition (Figure 10).
t
PV
t
PV
A
ACKNOWLEDGE
FROM SLAVE
A
DATA TO INTERRUPT MASK
DATA TO PORT
DATA 1 VALID
DATA 2
DATA 2
t
PV
t
PV
A
ACKNOWLEDGE
FROM SLAVE
A
DATA 2 VALID