1997 Apr 02
data from port
data from port
0
DATA 4
A2
A1
A0
1
A
DATA 1
A
1
P
R/W
acknowledge
from slave
acknowledge
from slave
stop
condition
Philips Semiconductors
slave address (PCF8574)
SDA
S
0
1
0
start condition
Remote 8-bit I/O expander for I
2
C-bus
READ FROM
PORT
10
DATA 2
t ph
t ps
DATA 3
DATA 4
t ir
t ir
MBD975
DATA INTO
PORT
INT
t iv
A LOW-to-HIGH transition of SDA, while SCL is HIGH is defined as the stop condition (P). 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.
PCF8574
Product specification
htdiwegap lluf ,koobdnah
Fig.11 READ mode (input).
PHILIPS [ NXP SEMICONDUCTORS ]
