24AA04-I/SNG Microchip Technology, 24AA04-I/SNG Datasheet - Page 13

• 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

5.6
A control byte is the first byte received following the
Start condition from the master device (Figure 5-3).
The control byte begins with a four-bit control code. For
the 24XX, this is set as ‘
operations. The next three bits of the control byte are
the block-select bits (B2, B1, B0). They are used by the
master device to select which of the 256-word blocks of
memory are to be accessed. These bits are in effect the
three Most Significant bits of the word address. Note
that B2, B1 and B0 are “don’t care” for the 24XX00, the
24XX01 and 24XX02. B2 and B1 are “don’t care” for
the 24XX04. B2 is “don’t care” for the 24XX08.
FIGURE 5-3:
© 2007 Microchip Technology Inc.
x = “don’t care” bit
24XX016
24XX02
24XX04
24XX08
24XX00
24XX01
Device Addressing For Devices
Without Functional Address Pins
Start bit
S
S
S
S
S
S
CONTROL AND ADDRESS BYTE ASSIGNMENTS FOR
DEVICES WITHOUT ADDRESS PINS
1010’
1
1
1
1
1
1
Control Code
0
0
0
0
0
0
binary for read and write
1
1
1
1
1
1
Control Byte
0
0
0
0
0
0
Block Select bits
B2 B1 B0
x
x
x
x
x
B1 B0
x
x
x
x
B0
x
x
x
24AAXX/24LCXX/24FCXX
R/W
R/W
R/W
R/W
R/W
R/W
Read/Write bit (Read = 1, Write = 0)
ACK
ACK
ACK
ACK
ACK
ACK
The last bit of the control byte defines the operation to
be performed. When set to ‘
selected. When set to ‘
Following the Start condition, the 24XX monitors the
SDA bus. Upon receiving a ‘
select bits and the R/W bit, the slave device outputs an
Acknowledge signal on the SDA line. The address byte
follows the acknowledge.
Acknowledge
bit
x
x
A7
A7
A7
A7
A6
x
.
.
.
.
0
’ a write operation is selected.
Address Byte
x
.
.
.
.
.
1
1010’
x
.
.
.
.
.
’, a read operation is
A3
.
.
.
.
.
DS21930C-page 13
code, the block
.
.
.
.
.
.
.
.
.
.
.
.
A0
A0
A0
A0
A0
A0