pca9551bs3 NXP Semiconductors, pca9551bs3 Datasheet - Page 10

• Manufacturer Part Number: pca9551bs3
• Description: 8-bit I2c Led Driver With Programmable Blink Rates
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA9551_7
Product data sheet
Fig 11. Write to register
Fig 12. Read from register
Fig 13. Read Input Port register
data into
SDA
read from
(cont.)
SDA
Remark: This figure assumes the command byte has previously been programmed with 00h.
write to register
data out from port
port
SCL
SDA
port
S
START condition
S
START condition
S
(repeated)
START condition
1
1
1
S
START condition
7.4 Bus transactions
1
1
2
1
slave address
1
1
slave address
0
slave address
3
0
1
0
slave address
0 A2 A1 A0 0
4
0 A2 A1 A0
0
0 A2 A1 A0
5
0 A2 A1 A0 1
acknowledge
6
from slave
acknowledge
7
R/W
from slave
R/W
R/W
8
0
t
h(D)
1
R/W
A
9
A
acknowledge
from slave
A
0
A
0
acknowledge
from slave
0
DATA 2
Rev. 07 — 23 February 2007
0
at this moment master-transmitter becomes master-receiver
and slave-receiver becomes slave-transmitter
command byte
0
data from register
command byte
DATA (first byte)
0
Auto-Increment
register address
if AI = 1
AI
AI
data from port
0 B2 B1
DATA 1
8-bit I
DATA 3
0 B2 B1 B0
acknowledge
from slave
2
C-bus LED driver with programmable blink rates
B0
t
A
su(D)
A
acknowledge
from slave
A
acknowledge
from master
(cont.)
A
acknowledge
from master
data to register
DATA 4
DATA 1
data from port
data from register
DATA (last byte)
DATA 4
t
no acknowledge
v(Q)
from master
A
acknowledge
from slave
PCA9551
NA
© NXP B.V. 2007. All rights reserved.
DATA 1 VALID
no acknowledge
from master
NA
002aac509
002aac507
P
STOP
condition
002aac508
P
STOP
condition
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