is24c02a Integrated Silicon Solution, Inc., is24c02a Datasheet - Page 7
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is24c02a
Manufacturer Part Number
is24c02a
Description
Serial Eeprom
Manufacturer
Integrated Silicon Solution, Inc.
Datasheet
1.IS24C02A.pdf
(22 pages)
Available stocks
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Quantity
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Part Number:
is24c02a-25LI
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IS24C02A IS24C04A IS24C08A IS24C16A
DEVICE ADDRESSInG
The Master begins a transmission by sending a Start
condition. The Master then sends the address of the
particular Slave devices it is requesting. The Slave device
(Fig. 5) address is 8 bits.
The four most significant bits of the Slave address are
fixed as 1010 for the IS2402A/04A/08A/16A.
The next three bits of the Slave address are specific for
each of the EEPROM. The bit values enable access to
multiple memory blocks or multiple devices.
The IS24C02A uses the three bits A0, A1, and A2 in a
comparison with the hard-wired input values on the A0,
A1, and A2 pins. Up to eight IS24C02A units may share
the 2-wire bus.
The IS24C04A uses the bit B0 to address either the upper
or the lower 256 byte block in the device. Also, the bits
A1 and A2 are used in a comparison with the hard-wired
input values on the A1 and A2 pins. Up to four IS24C04A
units may share the 2-wire bus.
The IS24C08A uses the bits B0 and B1 to address one
of the four 256 byte blocks in the device. Also, the bit A2
is used in a comparison with the hard-wired input value
on the A2 pin. Up to two IS24C08A units may share the
2-wire bus.
The IS24C16A uses the bits B0, B1, and B2 to address
one of the eight 256 byte blocks in the device.
The last bit of the Slave address specifies whether a Read
or Write operation is to be performed. When this bit is set
to 1, a Read operation is selected, and when set to 0, a
Write operation is selected.
After the Master transmits the Start condition and Slave
address byte (Fig. 5), the appropriate 2-wire Slave (eg.
IS24C02A/04A/08A/16A) will respond with ACK on the
SDA line. The Slave will pull down the SDA on the ninth
clock cycle, signaling that it received the eight bits of data.
The selected EEPROM then prepares for a Read or Write
operation by monitoring the bus.
Integrated Silicon Solution, Inc. — www.issi.com
Rev. J
11/10/08
Page Write
The IS24C02A/04A/08A/16A is capable of 16-byte Page-
Write operation. A Page-Write is initiated in the same
manner as a Byte Write, but instead of terminating the
internal Write cycle after the first data word is transferred,
the Master device can transmit up to 15 more bytes. After
the receipt of each data word, the EEPROM responds
immediately with an ACK on SDA line, and the four lower
order data word address bits are internally incremented by
one, while the higher order bits of the data word address
remain constant. If a byte address is incremented from
the last byte of a page, it returns to the first byte of that
page. If the Master device should transmit more than
16 bytes prior to issuing the Stop condition, the address
counter will “roll over,” and the previously written data will
be overwritten. Once all 16 bytes are received and the
Stop condition has been sent by the Master, the internal
programming cycle begins. At this point, all received data
is written to the IS24C02A/04A/08A/16A in a single Write
cycle. All inputs are disabled until completion of the internal
Write cycle.
Acknowledge (ACK) Polling
The disabling of the inputs can be used to take advantage
of the typical Write cycle time. Once the Stop condition
is issued to indicate the end of the host's Write operation,
the IS24C02A/04A/08A/16A initiates the internal Write
cycle. ACK polling can be initiated immediately. This
involves issuing the Start condition followed by the Slave
address for a Write operation. If the EEPROM is still
busy with the Write operation, no ACK will be returned. If
the IS24C02A/04A/08A/16A has completed the Write
operation, an ACK will be returned and the host can then
proceed with the next Read or Write operation.
WRITE OPERATIOn
byte Write
In the Byte Write mode, the Master device sends the
Start condition and the Slave address information (with
the R/W set to Zero) to the Slave device. After the Slave
generates an ACK, the Master sends the byte address
that is to be written into the address pointer of the
IS24C02A/04A/08A/16A. After receiving another ACK
from the Slave, the Master device transmits the data
byte to be written into the address memory location. The
IS24C02A/04A/08A/16A acknowledges once more and
the Master generates the Stop condition, at which time the
device begins its internal programming cycle. While this
internal cycle is in progress, the device will not respond
to any request from the Master device.
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