S-24C08C Datasheet, PDF (15/33 Pages) Seiko Instruments Inc – Write protect function during the low power supply voltage

Rev.1.0_00_H
2-WIRE SERIAL E²PROM
S-24C08C (WLP PRODUCT)
6. 4 Acknowledge polling
Acknowledge polling is used to know the completion of the write cycle in the S-24C08C.
After the S-24C08C receives a stop condition and once starts the write cycle, all operations are inhibited and no
response is made to the signal transmitted by the master device.
Accordingly the master device can recognize the completion of the write cycle in the S-24C08C by detecting a
response from the slave device after transmitting the start condition, the device address and the read / write
instruction code to the S-24C08C (slave device).
That is, if the S-24C08C does not generate an acknowledgment signal, the write cycle is in progress and if the
S-24C08C generates an acknowledgment signal, the write cycle has been completed.
It is recommended to use the read instruction “1” as the read / write instruction code transmitted by the master
device.
Acknowledge polling during write
DATA
SS
TT
OA
PR
T
W
R
I
T
E
SDA
LINE
D2 D1 D0
DEVICE
ADDRESS
0
RN
/A
W
C
K
S
T
A
R
T
W
R
I
T
E
DEVICE
ADDRESS
0
WORD
ADDRESS
RA
A
/C
C
WK
K
t_WR
Acknowledge polling during read
DATA
SS
TT
OA
PR
T
R
E
A
D
SDA
LINE
D2 D1 D0
DEVICE
ADDRESS
1
RN
/A
W
C
K
NO ACK from
S
T
A
R
T
R ^{Master Device}
E
A
D
DEVICE
ADDRESS
1
DATA
RA
/C
WK
SS
TT
OA
PR
T
DEVICE
ADDRESS
RA
/C
WK
t_WR
Remark
Users are able to input word address and data after ACK output in acknowledge polling during write.
Users are able to read data after ACK output in acknowledge polling during read. However, after that users
input the write instruction, a start condition may not be input during data output. Input a stop condition and the
next instruction after data output and ACK output.
Figure 14 Usage Example of Acknowledge Polling
15