Write Operation; Read Operation At Specific Address - Micro crystal RV-1805-C3 Applications Manual

Micro Crystal
Extrem Low Power Real Time Clock / Calendar Module
4.2.8.

WRITE OPERATION

Master transmits to Slave-Receiver at specified address. The Register Address is an 8-bit value that defines which
register is to be accessed next. After reading or writing one byte, the Register Address is automatically incremented
by 1.
1) Master sends out the START condition.
2) Master sends out Slave Address, D2h for the RV-1805-C3; the R/
3) Acknowledgement from the RV-1805-C3.
4) Master sends out the Register Address to the RV-1805-C3.
5) Acknowledgement from the RV-1805-C3.
6) Master sends out the Data to write to the specified address in step 4).
7) Acknowledgement from the RV-1805-C3.
8) Steps 6) and 7) can be repeated if necessary. The address will be incremented automatically in the
RV-1805-C3.
9) Master sends out the STOP Condition.
1 2
S
SLAVE ADDRESS
4.2.9.

READ OPERATION AT SPECIFIC ADDRESS

Master reads data after setting Register Address:
1) Master sends out the START condition.
2) Master sends out Slave Address, D2h for the RV-1805-C3; the R/
3) Acknowledgement from the RV-1805-C3.
4) Master sends out the Register Address to the RV-1805-C3.
5) Acknowledgement from the RV-1805-C3.
6) Master sends out the RESTART condition (STOP condition followed by START condition)
7) Master sends out Slave Address, D3h for the RV-1805-C3; the R/
8) Acknowledgement from the RV-1805-C3.
At this point, the Master becomes a Receiver, the Slave becomes the Transmitter.
9) The Slave sends out the Data from the Register Address specified in step 4).
10) Acknowledgement from the Master.
11) Steps 9) and 10) can be repeated if necessary.
The address will be incremented automatically in the RV-1805-C3.
12) The Master, addressed as Receiver, can stop data transmission by not generating an acknowledge on the
last byte that has been sent from the Slave-Transmitter. In this event, the Slave-Transmitter must leave the
data line HIGH to enable the Master to generate a STOP condition.
13) Master sends out the STOP condition.
1 2
S 0 A
SLAVE ADDRESS
3 4
0 A
REGISTER ADDRESS
3 4 5 6
A S
REGISTER ADDRESS
RESTART
Acknowledge from RV-1805-C3
W
5 6
A
DATA
Acknowledge from RV-1805-C3
W
W
7 8
1 A
SLAVE ADDRESS
bit is a 0 indicating a write operation.
7 8
A
DATA
bit is a 0 indicating a write operation.
bit is a 1 indicating a read operation.
9 10
A
DATA
Acknowledge from Master
RV-1805-C3
9
A P
11 12 13
A P
DATA
No acknowledge
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