S-7750C Datasheet, PDF (21/44 Pages) Seiko Instruments Inc – PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E2PROM CIRCUIT)

PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E²PROM CIRCUIT)
Rev.1.1_00
S-7750C
5. Read operation
When the S-7750C receives the 7-bit device address and the Read / Write instruction code “1” after receiving a start
condition, it generates an acknowledgment signal.
Next, 8-bit data is output from the S-7750C synchronizing with the SCL clock.
After that, the master device sends a stop condition, not an acknowledgment signal in order to finish the Read
operation.
S
T
R
A
E
R
A
T
DEVICE
D
ADDRESS
NO ACK from
Master Device
S
T
O
P
DATA
SDA LINE
D D D TA
C C C _{/ C2 C1 C0 1}
2 1 0C
B7 B6 B5 B4 B3 B2 B1 B0
M
LR A
S
S/ C
B
BW K
Figure 25 Read
6. Write operation
6. 1 Write
When the S-7750C receives the 7-bit device address and the Read / Write instruction code “0” after receiving a start
condition, it generates an acknowledgment signal.
Next, after it receives the 8-bit word address and generates an acknowledgment signal, it receives a stop condition to
finish the Write command.
In the Write operation to the E²PROM, the Write operation starts with a stop condition, the S-7750C finishes it after
the period to Write (max. 5 ms) has elapsed. During Write to the E²PROM, all operations are inhibited to be performed
and the S-7750C does not send back any acknowledgment signals for command inputs.
S
W
T
R
A
I
R
T
T
DEVICE
E
ADDRESS
S
T
O
P
DATA
SDA LINE
D D D TA
C C C _/ C2 C1 C0 0
2 10C
B7 B6 B5 B4 B3 B2 B1 B0
M
LR A
S
S/ C
B
BW K
A
C
K
Remark Users are not necessary to input data (8-bit) and the next acknowledgment for the reload command, the
switching access to register / E²PROM command. If inputting data in this timing, data is regarded as
dummy, the next acknowledgement signal is generated.
Figure 26 Byte write
Seiko Instruments Inc.
21