X24026

3

DEVICE OPERATION

The X24026 supports a bidirectional bus oriented proto-

col. The protocol defines any device that sends data onto

the bus as a transmitter and the receiving device as the

receiver. The device controlling the transfer is a master

and the device being controlled is the slave. The master

will always initiate data transfers and provide the clock for

both transmit and receive operations. Therefore, the

X24026 will be considered a slave in all applications.

Clock and Data Conventions

Data states on the SDA line can change only during SCL

LOW. SDA state changes during SCL HIGH are reserved

for indicating start and stop conditions. Refer to Figures 1

and 2.

Start Condition

All commands are preceded by the start condition, which

is a HIGH to LOW transition of SDA when SCL is HIGH.

The X24026 continuously monitors the SDA and SCL

lines for the start condition and will not respond to any

command until this condition has been met.

Figure 1. Data Validity

SCL

SDA

DATA STABLE

DATA

CHANGE

7020 FRM 03