S-24C256C Datasheet, PDF (13/35 Pages) Seiko Instruments Inc – Write protect function during the low power supply voltage

Rev.2.0_02_S
2-WIRE SERIAL E²PROM
S-24C256C
6. 2 Page write
The page write mode allows up to 64 bytes to be written in a single write operation in the S-24C256C.
Its basic process to transmit data is as same as byte write, but it operates page write by sequentially receiving
8-bit write data as much data as the page size has.
When the S-24C256C receives a 7-bit device address and a 1-bit read / write instruction code set to “0”, following
a start condition, it generates an acknowledge. And the S-24C256C receives a upper 8-bit word address, and
responds with an acknowledge. Then the S-24C256C receives a lower 8-bit word address, and responds with an
acknowledge. After the S-24C256C receives 8-bit write data and responds with an acknowledge, it receives 8-bit
write data corresponding to the next word address, and generates an acknowledge. The S-24C256C repeats
reception of 8-bit write data and generation of acknowledge in succession. The S-24C256C can receive as many
write data as the maximum page size.
Receiving a stop condition initiates a write cycle of the area starting from the designated memory address and
having the page size equal to the received write data.
S
W
T
R
A
I
R
DEVICE
T
UPPER
LOWER
T
ADDRESS E WORD ADDRESS (n)
WORD ADDRESS (n)
SDA LINE
1 0 1 0 A2 A1 A0 0 _{X W14 W13 W12 W11 W10 W9 W8 W7 W6 W5 W4 W3 W2 W1 W0 D7}
M
LR A
A
A
S
S/ C
C
C
B
BW K
K
K
DATA (n)
S
T
O
DATA (n+x)
P
D0 D7
D0
Figure 13 Page Write
In the S-24C256C, the lower 6 bits of the word address are automatically incremented every time when the
S-24C256C receives 8-bit write data. If the size of the write data exceeds 64 bytes, the upper 9 bits of the word
address remain unchanged, and the lower 6 bits are rolled over and the last 64-byte data that the S-24C256C
received will be overwritten.
13