RV-8523 Datasheet, PDF (43/57 Pages) MICORO CRYSTAL SWITZERLAND – Real Time Clock

Micro Crystal
Real Time Clock / Calendar Module
RV-8523
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 are connected to a positive supply via pull-up
resistors. Data transfer is 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 remains stable during the HIGH
period of the clock pulse, as changes in the data line at this time are interpreted as a control signals. Data changes
should be executed during the LOW period of the clock pulse (see figure below).
Bit transfer:
10.2. START AND STOP CONDITIONS
Both data and 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) (see figure below).
Definition of START and STOP conditions:
For this device, a repeated START is not allowed. Therefore, a STOP has to be released before the next START.
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