RV-8564 Datasheet, PDF (23/40 Pages) MICORO CRYSTAL SWITZERLAND – I2C-Bus Interface Real Time Clock

Micro Crystal
Real Time Clock / Calendar Module
RV-8564
10.CHARACTERISTICS OF THE I²C BUS
The I²C bus is for bidirectional, two-line communication between different ICs or modules. The two lines are a
Serial Data Line (SDA) and a Serial Clock Line (SCL). Both lines must be connected to a positive supply via pull-up
resistors. Data transfer may be initiated only when the bus is not busy.
10.1. BIT TRANSFER
One data bit is transferred during each clock pulse. The data on the SDA line must remain stable during the HIGH
period of the clock pulse, as changes in the data line at this time will be interpreted as a control signal. Data
changes should be executed during the LOW period of the clock pulse.
10.2. START AND STOP CONDITIONS
Both SDA data and SCL clock lines remain HIGH when the bus is not busy.
A HIGH-to-LOW transition of the data line, while the clock is HIGH, is defined as the START condition (S).
A LOW-to-HIGH transition of the data line, while the clock is HIGH, is defined as the STOP condition (P).
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