SCL
command byte
data to port 0
1
acknowledge
from slave
acknowledge
from slave
0
A
0.7
A
DATA 0
0.0
A 1.7
DATA 1
1.0
P
data to port 1
1
4
5
6
7
8
2
3
9
Philips Semiconductors
2004 Sep 30
0
R/W
acknowledge
from slave
A2 A1 A0
0
A
0
0
0
0
0
0
t
pv
DATA VALID
t
pv
slave address
SDA
S
0
1
0
start condition
WRITE TO
PORT
DATA OUT
FROM PORT 0
DATA OUT
FROM PORT 1
SU01442
Figure 6. WRITE to output port registers
SCL
command byte
data to register
1
acknowledge
from slave
0
A MSB
DATA 0
LSB
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
1
2
3
4
5
data to register
16-bit I
2
C and SMBus I/O port with interrupt
8
0
R/W
acknowledge
from slave
A2 A1 A0
0
A
0
0
0
0
0
1
slave address
SDA
S
0
1
0
A MSB
acknowledge
from slave
DATA 1
LSB
A
P
start condition
SU01443
Figure 7. WRITE to configuration registers
PCA9555
Product data sheet
PHILIPS [ NXP SEMICONDUCTORS ]
