pca9655e ON Semiconductor, pca9655e Datasheet - Page 12

• Manufacturer Part Number: pca9655e
• Description: Pca9655e Remote 16-bit I/o Expander For I2c Bus With Interrupt
• Manufacturer: ON Semiconductor

Remark: Transfer of data can be stopped at any moment by a STOP condition. When this occurs, data present at the latest acknowledge
phase is valid (output mode). It is assumed that the command byte has previously been set to ’00’ (read Input Port register).
SDA
read from port 0
data into port 0
read from port 1
data into port 1
SCL
INT
SDA
(cont.)
START condition
S A6
Remark: Transfer can be stopped at any time by a STOP condition.
1
S
START condition
t
A5 A4 A3
2
v(INT_N)
S
(repeated)
START condition
A6
slave address
3
A6
A5 A4 A3
4
slave address
A5 A4 A3
A2 A1 A0 1 A
5
acknowledge
slave address
from slave
6
7
R/W
A2 A1 A0
8
A2 A1 A0
9
acknowledge
7
from slave
acknowledge
t
6 5 4 3 2 1 0
rst(INT_N)
R/W
from slave
Figure 9. Read from Input Port Register, Scenario 1
0
R/W
1
I0.x
A
acknowledge
A
from master
MSB
Figure 8. Read from Register
COMMAND BYTE
upper byte of register
data from lower or
at this moment master−transmitter becomes master−receiver
and slave−receiver becomes slave−transmitter
A
DATA (first byte)
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7
6 5 4 3 2 1 0
acknowledge
I1.x
12
from slave
acknowledge
from master
LSB
A
A
A
A
acknowledge
from master
(cont.)
7
6 5 4 3 2 1 0
MSB
I0.x
lower byte of register
data from upper or
acknowledge
DATA (last byte)
from master
no acknowledge
A
7
from master
6 5 4 3 2 1 0
LSB
I1.x
non acknowledge
NA
from master
P
STOP condition
STOP
condition
1
P