R1EX24064ASAS0A_15 Datasheet, PDF (13/26 Pages) Renesas Technology Corp – Two-wire serial interface 64k EEPROM (8-kword × 8-bit)

R1EX24064AxxS0A
Device Addressing
The EEPROM device requires an 8-bit device address word following a start condition to enable the chip
for a read or a write operation. The device address word consists of 4-bit device code, 3-bit device
address code and 1-bit read/write(R/W) code. The most significant 4-bit of the device address word are
used to distinguish device type and this EEPROM uses “1010” fixed code. The device address word is
followed by the 3-bit device address code in the order of A2, A1, A0. The device address code selects one
device out of all devices which are connected to the bus. This means that the device is selected if the
inputted 3-bit device address code is equal to the corresponding hard-wired A2-A0 pin status. The
eighth bit of the device address word is the read/write(R/W) bit. A write operation is initiated if this bit is
low and a read operation is initiated if this bit is high. Upon a compare of the device address word, the
EEPROM enters the read or write operation after outputting the zero as an acknowledge. The EEPROM
turns to a stand-by state if the device code is not “1010” or device address code doesn’t coincide with
status of the correspond hard-wired device address pins A0 to A2.
Device Address Word
Device address word (8-bit)
Device code (fixed)
64k
1
0
1
0
Note: 1. R/W=“1” is read and R/W = “0” is write.
Device address code
A2
A1
A0
R/W code*¹
R/W
REJ03C0332-0200 Rev.2.00 Oct. 26, 2009
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