X24026
DEVICE OPERATION
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.
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.
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
3
XICOR [ XICOR INC. ]
