X24C01A Datasheet, PDF (2/13 Pages) Xicor Inc. – Serial E2PROM

X24C01A
PIN DESCRIPTIONS
Serial Clock (SCL)
The SCL input is used to clock all data into and out of the
device.
Serial Data (SDA)
SDA is a bidirectional pin used to transfer data into and
out of the device. It is an open drain output and may be
wire-ORed with any number of open drain or open
collector outputs.
An open drain output requires the use of a pull-up
resistor. For selecting typical values, refer to the Guide-
lines for Calculating Typical Values of Bus Pull-Up
Resistors graph.
Address (A₀, A₁, A₂)
The address inputs are used to set the least significant
three bits of the seven bit slave address. These inputs
can be static or actively driven. If used statically they
must be tied to V_SS or V_CC as appropriate. If actively
driven, they must be driven to V_SS or to V_CC.
WRITE CONTROL (WC)
The Write Control input controls the ability to write to the
device. When WC is LOW (tied to V_SS) the X24C01A will
be enabled to perform write operations. When WC is
HIGH (tied to V_CC) the internal high voltage circuitry will
be disabled and all writes will be disabled.
DEVICE OPERATION
The X24C01A supports a bidirectional bus oriented
protocol. 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 trans-
fer 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 opera-
tions. Therefore, the X24C01A will be considered a
slave in all applications.
PIN CONFIGURATION
A0
A1
A2
VSS
DIP/SOIC
1
8
2
7
X24C01A
3
6
4
5
VCC
WC
SCL
SDA
3841 FHD F02
PIN NAMES
Symbol
A₀–A₂
SDA
SCL
WC
V_SS
V_CC
Description
Address Inputs
Serial Data
Serial Clock
Write Control
Ground
+5V
3841 PGM T01
Clock and Data Conventions
Data states on the SDA line can change only during SCL
LOW. SDA state changes during SCL HIGH are re-
served 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 X24C01A continuously monitors the SDA
and SCL lines for the start condition and will not respond
to any command until this condition has been met.
2