pca9557bs NXP Semiconductors, pca9557bs Datasheet - Page 12

• Manufacturer Part Number: pca9557bs
• Description: 8-bit I2c And Smbus I/0 Port With Reset
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA9557_5
Product data sheet
Fig 16. Read from register
Fig 17. Read input port register
data into
SDA
read from
(cont.)
Remark: This figure assumes the command byte has previously been programmed with 00h.
Transfer of data can be stopped at any moment by a STOP condition. When this occurs, data present at the last
acknowledge phase is valid (output mode). Input data is lost.
port
SDA
port
S
START condition
S
(repeated)
START condition
0
S
START condition
0
0
slave address
0
0
1
slave address
0
1
slave address
1 A2 A1 A0 0
1
1 A2 A1 A0
DATA 1
1 A2 A1 A0 1
acknowledge
from slave
acknowledge
R/W
from slave
R/W
t
h(D)
1
R/W
A
A
A
acknowledge
from slave
Rev. 05 — 12 September 2007
DATA 2
at this moment master-transmitter becomes master-receiver
and slave-receiver becomes slave-transmitter
command byte
data from register
DATA (first byte)
data from port
DATA 1
DATA 3
acknowledge
from slave
t
A
su(D)
8-bit I
A
acknowledge
from master
(cont.)
A
acknowledge
from master
2
C-bus and SMBus I/O port with reset
DATA 4
data from port
data from register
DATA (last byte)
DATA 4
no acknowledge
from master
PCA9557
NA
© NXP B.V. 2007. All rights reserved.
no acknowledge
from master
NA
002aad284
P
STOP
condition
002aad283
P
STOP
condition
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