24AA04-I/SNG Microchip Technology, 24AA04-I/SNG Datasheet - Page 16

• Manufacturer Part Number: 24AA04-I/SNG
• Description: EEPROM Serial-I2C 4K-Bit 2Block x 256 x 8 1.8V/2.5V/3.3V/5V 8-Pin SOIC N Tube
• Manufacturer: Microchip Technology

Specifications of 24AA04-I/SNG

• Package: 8SOIC N
• Interface Type: Serial-I2C
• Density: 4 Kb
• Maximum Operating Frequency: 0.4 MHz
• Maximum Random Access Time: 900 ns
• Typical Operating Supply Voltage: 1.8|2.5|3.3|5 V
• Organization: 2Blockx256x8
• Data Retention: 200(Min) Year
• Operating Temperature: -40 to 85 °C

24AAXX/24LCXX/24FCXX
6.0
6.1
A byte write operation begins with a Start condition
from the master followed by the four-bit control code
(see Figure 6-1 and Figure 6-2). The next 3 bits are
either the Block Address bits (for devices without
address pins) or the Chip Select bits (for devices with
address pins). Then the master transmitter clocks the
R/W bit (which is a logic low) onto the bus. The slave
then generates an Acknowledge bit during the ninth
clock cycle.
The next byte transmitted by the master is the address
byte (for 128-bit to 16 Kbit devices) or the high-order
address byte (for 32-1024 Kbit devices). For 32 through
1024 Kbit devices, the high-order address byte is
followed by the low-order address byte. In either case,
each address byte is acknowledged by the 24XX and
the address bits are latched into the internal address
counter of the 24XX.
FIGURE 6-1:
FIGURE 6-2:
DS21930C-page 16
SDA Line
Bus Activity
Master
Bus Activity
Bus Activity
Master
SDA Line
Bus Activity
WRITE OPERATIONS
Byte Write
S
S
T
A
R
T
S
S
T
A
R
T
BYTE WRITE: 128-BIT TO 16 KBIT DEVICES
BYTE WRITE: 32 TO 1024 KBIT DEVICES
Control
Byte
Control
Byte
A
C
K
Address Byte
High Order
A
C
K
A
C
K
Address
Address Byte
Low Order
Byte
For the 24XX00 devices, only the lower four address
bits are used by the device. The upper four bits are
“don’t cares.”
After receiving the ACK from the 24XX acknowledging
the final address byte, the master device transmits the
data word to be written into the addressed memory
location. The 24XX acknowledges again and the
master generates a Stop condition, which initiates the
internal write cycle.
If an attempt is made to write to an array with the WP
pin held high, the device will acknowledge the
command, but no write cycle will occur, no data will be
written, and the device will immediately accept a new
command. After a byte Write command, the internal
address counter will increment to the next address
location. During a write cycle, the 24XX will not
acknowledge commands.
A
C
K
A
C
K
Data
Byte
© 2007 Microchip Technology Inc.
Data
Byte
A
C
K
O
S
T
P
P
A
C
K
P
S
T
O
P