RV-8564 Datasheet, PDF (26/40 Pages) MICORO CRYSTAL SWITZERLAND – I2C-Bus Interface Real Time Clock

Micro Crystal
Real Time Clock / Calendar Module
RV-8564
11.I²C BUS PROTOCOL
11.1. ADDRESSING
Before any data is transmitted on the I²C bus, the device which should respond is addressed first. The addressing
is always carried out with the first byte transmitted after the start procedure.
The RV-8564 acts as a Slave-Receiver or Slave-Transmitter. Therefore, the clock signal SCL is only an input
signal, but the data signal SDA is a bidirectional line.
RV-8564
Slave Address
11.2. CLOCK AND CALENDAR READ AND WRITE CYCLES
11.2.1. WRITE MODE
Master transmits to Slave-Receiver at specified address. The Word Address is 4-bit value that defines which
register is to be accessed next. The upper four bits of the Word Address are not used. After reading or writing one
byte, the Word Address is automatically incremented by 1.
1) Master sends out the “Start Condition”.
2) Master sends out the “Slave Address”, A2h for the RV-8564; the R/ W bit in write mode.
3) Acknowledgement from the RV-8564.
4) Master sends out the “Word Address” to the RV-8564.
5) Acknowledgement from the RV-8564.
6) Master sends out the “data” to write to the specified address in step 4).
7) Acknowledgement from the RV-8564.
8) Steps 6) and 7) can be repeated if necessary. The address will be incremented automatically in the RV-8564.
9) Master sends out the “Stop Condition”.
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