S-24C02DI-J8T1U5 Datasheet, PDF (19/47 Pages) Seiko Instruments Inc – Write protect function during low power supply voltage

Rev.3.0_01_U
2-WIRE SERIAL E²PROM
S-24C02D/04D/08D16D
8. 2 Random read
Random read is used to read the data at an arbitrary memory address.
A dummy write is performed to load the memory address into the address counter.
When this IC receives a 7-bit device address and a 1-bit read / write instruction code set to "0" following a start
condition, it responds with an acknowledge.
This IC then receives an 8-bit word address and responds with an acknowledge. The memory address is loaded
to the address counter in this IC by these operations. Reception of write data does not follow in a dummy write
whereas reception of write data follows in byte write and in page write.
Since the memory address is loaded into the memory address counter by dummy write, the master device can
read the data starting from the arbitrary memory address by transmitting a new start condition and performing the
same operation in the current address read.
That is, when this IC receives a 7-bit device address and a 1-bit read / write instruction code set to "1", following a
start condition signal, it responds with an acknowledge. Next, 8-bit data is transmitted from this IC in synchronous
to the SCL clock. The master device outputs stop condition not an acknowledge, the reading of this IC is ended.
S
W
S
T
R
T
A
R
DEVICE
S-24C02D _{T ADDRESS}
I
T
A
R
E _{WORD ADDRESS (n) T}
R
E
DEVICE A
ADDRESS D
NO ACK from
Master Device
DATA
S
T
O
P
SDA
LINE
1 0 1 0 A2 A1 A0 0 _{W7 W6 W5 W4 W3 W2 W1 W0}
1 0 1 0 A2 A1 A0 1 D7 D6 D5 D4 D3 D2 D1 D0
S-24C04D
SDA
LINE
1 0 1 0 A2 A1 P0 0 _{W7 W6 W5 W4 W3 W2 W1 W0}
1 0 1 0 A2 A1 X 1 D7 D6 D5 D4 D3 D2 D1 D0
S-24C08D
SDA
LINE
1 0 1 0 A2 P1 P0 0 _{W7 W6 W5 W4 W3 W2 W1 W0}
1 0 1 0 A2 X X 1 D7 D6 D5 D4 D3 D2 D1 D0
S-24C16D
SDA
LINE
1 0 1 0 P2 P1 P0 0 _{W7 W6 W5 W4 W3 W2 W1 W0}
M
LR A
A
S
S/ C
C
B
BW K
K
1 0 1 0 X X X 1 D7 D6 D5 D4 D3 D2 D1 D0
M
LR A
S
S/ C
B
BW K
DUMMY WRITE
Remark 1. X = Don't care
2. Set A0, A1, A2 to "0" in the product with SOT-23-5 package.
Figure 14 Random Read
19