at24hc04b ATMEL Corporation, at24hc04b Datasheet - Page 8

• Manufacturer Part Number: at24hc04b
• Description: Two-wire Serial Eeprom 4k 512 X 8
• Manufacturer: ATMEL Corporation

Figure 3-6.
4. Device Addressing
8
AT24HC04B
Output Acknowledge
DATA OUT
DATA IN
The 2K EEPROM device requires an 8-bit device address word following a start condition to
enable the chip for a read or write operation, as shown in
Figure 4-1.
The device address word consists of a mandatory “1”, “0” sequence for the first four most signif-
icant bits as shown. This is common to all the EEPROM devices.
The next two bits are the A2 and A1 device address bits for the 4K EEPROM. These two bits
must compare to their corresponding hardwired input pins. The A0 pin is a no-connect.
The eighth bit of the device address is the read/write operation select bit. A read operation is ini-
tiated if this bit is high, and a write operation is initiated if this bit is low.
Upon a compare of the device address, the EEPROM will output a “0”. If a compare is not made,
the chip will return to a standby state.
SCL
START
Device Address
1
4K
MSB
1
0
1
0
8
A
ACKNOWLEDGE
2
A
1
Figure
9
P
0
R/W
LSB
4-1.
5227D–SEEPR–1/08