R1EX24004ASAS0I Datasheet, PDF (11/24 Pages) Renesas Technology Corp – Two-wire serial interface 4k EEPROM (512-word × 8-bit)

R1EX24004AxxS0I
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 2-bit device address code A2, A1 memory adderess a8. The device address code selects one device
out of four devices which are connected to the bus. This means that the device is selected if the inputted 2-
bit device address code are equal to the corresponding hard-wired A2 , A1 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 “0” and a read operation is initiated if this bit is “1” . 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 A2 to A0.
Device Address Word
4k
Note:
Device address word (8-bit)
Device code (fixed)
1
0
1
0
1. R/W=“1” is read and R/W = “0” is write.
Device address code
A2
A1
a8
R/W code*¹
R/W
REJ03C0356-0001 Rev.0.01 Jan. 11, 2008
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