RV5C387A_03 Datasheet, PDF (26/49 Pages) RICOH electronics devices division – I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC WITH VOLTAGE MONITORING FUNCTION

RV5C387A
1.2-4 Data transmission write format in the RV5C387A
Although the I²C bus standard defines a transmission format for the slave address allocated for each IC,
transmission method of address information in IC is not defined. The RV5C387A transmits data the internal address
pointer (4bit) and the transmission format register (4bit) at the 1byte next to one which transmitted a slave address
and a write command. For write operation only one transmission format is available and (0000) is set to the
transmission format register. The 3byte transmits data to the address specified by the internal address pointer
written to the 2byte. Internal address pointer settings are automatically incremented for 4byte and after. Note that
when the internal address pointer is Fh, it will change to 0h on transmitting the next byte.
Example of data writing (When writing to internal address Eh to Fh)
R/W=0 (Write)
S01100100A11100000A
Data
A
Data
AP
Transmission of
slave address
(0110010)
Setting of
Eh to the
internal
address
pointer
Master to slave
Setting of
0h to the
trans-
mission
format
register
Writing of data to the
internal address Eh.
Slave to master
Writing of data to the
internal address Fh.
S Start condition
P Stop condition
A A A Acknowledge signal
26