FM24C02B Shanghai Fudan Microelectronics Co., Ltd., FM24C02B Datasheet - Page 11

• Manufacturer Part Number: FM24C02B
• Description: 2-wire Serial Eeprom
• Manufacturer: Shanghai Fudan Microelectronics Co., Ltd.

Write Operations
BYTE WRITE: A write operation requires an 8-bit
data word address following the device address
word and acknowledgment. Upon receipt of this
address, the EEPROM will again respond with a
zero and then clock in the first 8-bit data word.
Following receipt of the 8-bit data word, the
EEPROM will output a zero and the addressing
device, such as a microcontroller, must terminate
the write sequence with a stop condition. At this
time the EEPROM enters an internally timed write
cycle, t
disabled during this write cycle and the EEPROM
will not respond until the write is complete (refer to
Figure 8).
PAGE WRITE: The 2K EEPROM is capable of an
8-byte page write, and the 4K, 8K and 16K devices
are capable of 16-byte page writes.
A page write is initiated the same 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 seven (2K) or fifteen (4K, 8K, 16K)
more data words. The EEPROM will respond with
a
microcontroller must terminate the page write
sequence with a stop condition (refer to Figure 9).
The data word address lower three (2K) or four (4K,
8K, 16K) 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 following byte is placed at the beginning of the
same page. If more than eight (2K) or sixteen (4K,
8K, 16K) data words are transmitted to the EEPROM,
the data word address will “roll over” and previous
data will be overwritten.
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
read/write bit is representative of the operation
desired. Only if the internal write cycle has
completed will the EEPROM respond with a zero
allowing the read or write sequence to continue.
FM24C02B/04B/08B/16B 2-Wire Serial EEPROM
zero
WR,
after
to the nonvolatile memory. All inputs are
by
the
each
device
data
address
word
received.
word. The
The
Read Operations
Read operations are initiated the same way as write
operations with the exception that the read/write
select bit in the device address word is set to one.
There are three read operations: current address
read, random address read and sequential read.
CURRENT ADDRESS READ: The internal data
word address counter maintains the last address
accessed during the last read or write operation,
incremented by one. This address stays valid
between operations as long as the chip power is
maintained. The address “roll over” during read is
from the last byte of the last memory page to the
first byte of the first page. The address “roll over”
during write is from the last byte of the current
page to the first byte of the same page.
Once the device address with the read/write select
bit set to one is clocked in and acknowledged by
the EEPROM, the current address data word is
serially clocked out. The microcontroller does not
respond with an input zero but does generate a
following stop condition (refer to Figure 10).
RANDOM READ: A random read requires a “dummy”
byte write sequence to load in the data word
address. Once the device address word and data
word address are clocked in and acknowledged by
the EEPROM, the microcontroller must generate
another start condition. The microcontroller now
initiates a current address read by sending a
device address with the read/write select bit high.
The EEPROM acknowledges the device address
and serially clocks out the data word. The
microcontroller does not respond with a zero but
does generate a following stop condition (refer to
Figure 11).
SEQUENTIAL
initiated by either a current address read or a
random address read. After the microcontroller
receives a data word, it responds with an
acknowledge. As long as the EEPROM receives an
acknowledge, it will continue to increment the data
word address and serially clock out sequential data
words. When the memory address limit (2K、 8K、 16K)
is reached, the data word address will “roll over”
and the sequential read will continue. The
sequential read operation is terminated when the
microcontroller does not respond with a zero but
does generate a following stop condition (refer to
Figure 12)
Ver 1.6
READ:
Sequential
Data Sheet
reads
are
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