MAX7326 Maxim, MAX7326 Datasheet - Page 14

• Manufacturer Part Number: MAX7326
• Description: The MAX7326, a 2-wire serial-interfaced peripheral, features 12 push-pull outputs and four input ports with selectable internal pullups and transition detection
• Manufacturer: Maxim

I
and 4 Inputs
A write to the group A ports of the MAX7326 starts with
the master transmitting the group’s slave address with
the R/W bit set low. The MAX7326 acknowledges the
slave address and samples the ports during the
acknowledge. INT goes high (high impedance if an
external pullup resistor is not fitted) during the slave
address acknowledge. The master can then issue a
STOP condition after the acknowledge
typically the master proceeds to transmit one or more
bytes of data. The MAX7326 acknowledges these sub-
sequent bytes of data and updates the four output
ports and the 4-bit interrupt mask register with each
new byte until the master issues a STOP condition
(Figure
Figure 9. Writing to the Group A Ports of the MAX7326
Figure 10. Writing to the Group B Ports of the MAX7326
14
2
C Port Expander with 12 Push-Pull Outputs
______________________________________________________________________________________
FROM PORT
DATA OUT
9).
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 MAX7326
5
5
6
6
7
7
R/W
8
0
(Figure
R/W
0
8
A
ACKNOWLEDGE
FROM SLAVE
A
6), but
DATA TO INTERRUPT MASK
DATA TO PORT
DATA 1
DATA 1
A write to the group B ports of the MAX7326 starts with
the master transmitting the group’s slave address with
the R/W bit set low. The MAX7326 acknowledges the
slave address and samples the ports during the
acknowledge bit. The master can now transmit one or
more bytes of data. The MAX7326 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
t
PV
t
PV
A
ACKNOWLEDGE
FROM SLAVE
A
DATA TO INTERRUPT MASK
DATA TO PORT
DATA 1 VALID
DATA 2
(Figure
DATA 2
10).
t
PV
t
PV
A
ACKNOWLEDGE
FROM SLAVE
A
DATA 2 VALID