AT24C512BW-SH-T Atmel, AT24C512BW-SH-T Datasheet - Page 9

IC EEPROM 512KBIT 1MHZ 8SOIC

AT24C512BW-SH-T

Manufacturer Part Number
AT24C512BW-SH-T
Description
IC EEPROM 512KBIT 1MHZ 8SOIC
Manufacturer
Atmel
Datasheet

Specifications of AT24C512BW-SH-T

Format - Memory
EEPROMs - Serial
Memory Type
EEPROM
Memory Size
512K (64K x 8)
Speed
1MHz
Interface
I²C, 2-Wire Serial
Voltage - Supply
1.8 V ~ 3.6 V
Operating Temperature
-40°C ~ 85°C
Package / Case
8-SOIC (5.3mm Width), 8-SOP, 8-SOEIAJ
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
4. Device Addressing
5. Write Operations
5297A–SEEPR–1/08
The 512K EEPROM requires an 8-bit device address word following a start condition to enable
the chip for a read or write operation (see
sists of a mandatory “1”, “0” sequence for the first four most significant bits as shown. This is
common to all two-wire EEPROM devices.
The 512K uses the three device address bits A2, A1, A0 to allow as many as eight devices on
the same bus. These bits must compare to their corresponding hardwired input pins. The A2, A1
and A0 pins use an internal proprietary circuit that biases them to a logic low condition if the pins
are allowed to float.
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 device will return to a standby state.
DATA SECURITY: The AT24C512B has a hardware data protection scheme that allows the user
to Write Protect the whole memory when the WP pin is at V
BYTE WRITE: A write operation requires two 8-bit data word addresses following the device
address word and acknowledgment. Upon receipt of this address, the EEPROM will again
respond with a “0” and then clock in the first 8-bit data word. Following receipt of the 8-bit data
word, the EEPROM will output a “0”. The addressing device, such as a microcontroller, then
must terminate the write sequence with a stop condition. At this time the EEPROM enters an
internally-timed write cycle, t
write cycle and the EEPROM will not respond until the write is complete (see
10).
PAGE WRITE: The 512K EEPROM is capable of 128-byte page writes.
A page write is initiated the same way as a byte write, but the microcontroller does not send a
stop condition after the first data word is clocked in. Instead, after the EEPROM acknowledges
receipt of the first data word, the microcontroller can transmit up to 127 more data words. The
EEPROM will respond with a “0” after each data word received. The microcontroller must termi-
nate the page write sequence with a stop condition (see
The data word address lower 7 bits are internally incremented following the receipt of each data
word. The higher data word address bits are not incremented, retaining the memory page row
location. When the word address, internally generated, reaches the page boundary, the follow-
ing byte is placed at the beginning of the same page. If more than 128 data words are
transmitted to the EEPROM, the data word address will “roll over” and previous data will be
overwritten. The address roll over during write is from the last byte of the current page to the first
byte of the same page.
ACKNOWLEDGE POLLING: Once the internally-timed write cycle has started and the
EEPROM inputs are disabled, acknowledge polling can be initiated. This involves sending a
start condition followed by the device address word. The Read/Write bit is representative of the
operation desired. Only if the internal write cycle has completed will the EEPROM respond with
a “0”, allowing the read or write sequence to continue.
WR
, to the nonvolatile memory. All inputs are disabled during this
Figure 6-1 on page
Figure 6-3 on page
CC
10). The device address word con-
.
AT24C512B
11).
Figure 6-2 on page
9

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