Micro Crystal

Real Time Clock / Calendar Module

RV-8564

26/40

11.I

11.1.ADDRESSING

Before any data is transmitted on the I

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”.