CAT9554 CATALYST [Catalyst Semiconductor], CAT9554 Datasheet - Page 11

• Manufacturer Part Number: CAT9554
• Description: 8-bit I2C and SMBus I/O Port with Interrupt
• Manufacturer: CATALYST [Catalyst Semiconductor]

S
Power-On Reset Operation
When the power supply is applied to V
power-on reset pulse holds the CAT9554/9554A in a
reset state until V
READ FROM
© 2006 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
DATA INTO
0
1
PORT
PORT
SDA
SCL
INT
slave address
0
acknowledge from slave
t IV
start condition
0 A2
S
1
0
CC
2
A1
1
reaches V
A0
slave address
3
0
R/W
0
4
0 A2
A
5
DATA 1
POR
acknowledge
A1
6
from slave
level. At this point, the
A0
COMMAND BYTE
7
t PH
acknowledge from slave
t IR
R/W
CC
1
8
Figure 12. Read Input Port Register
pin, an internal
Figure 11. Read from Register
9
A
DATA 2
At this moment master-transmitter becomes
acknowledge from master
data from port
A
DATA 1
11
master-receiver and slave-receiver
S
DATA 3
reset condition is released and the internal state ma-
chine and the CAT9554/9554A registers are initialized
to their default state.
0
becomes slave-transmitter
t PS
1
slave address
acknowledge from slave
0
0
A
A2 A1 A0
no acknowledge from master
R/W
1
A
data from port
DATA 4
DATA 4
data from register
CAT9554, CAT9554A
data from register
last byte
DATA
no acknowledge
first byte
DATA
from master
Doc. No. 25088, Rev. B
acknowledge
from master
NA
stop
condition
P
NA
A
P