How the I2C Bus Works - EEWeb

Totem Output I 2 C I/O Expanders - Registers
• To configure the device
S Address W A 03H A
S Address W A 02 A
H
• To program the outputs
S Address W A 01H A
• To read input values
CONFIG
DATA
POLARITY
DATA
OUTPUT
DATA
No need to access
Configuration and
Polarity registers
once programmed
Semiconductors 38
A
A P
A P
Multiple writes are
possible during the
same communication
S Address W A 00 A H Multiple reads are
S R
Address R
A
INPUT
DATA
A P
possible during the
same communication