Features; Functional Descriptions; Two-Wire Serial Interface; Start And Stop Conditions - Holtek HT32F50231 User Manual

32-Bit Arm ® Cortex ® -M0+ MCU
HT32F50231/HT32F50241

Features

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Two-wire I C serial interface
2
● Serial data line (SDA) and serial clock (SCL)
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Multiple speed modes
● Standard mode – 100 kHz
● Fast mode – 400 kHz
● Fast mode plus – 1 MHz
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Bidirectional data transfer between master and slave
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Multi-master bus – no central master
● The same interface can act as Master or Slave
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Arbitration among simultaneously transmitting masters without corrupting serial data on the bus
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Clock synchronization
● Allow devices with different bit rates to communicate via one serial bus
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Supports 7-bit and 10-bit addressing mode and general call addressing
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Multiple slave addresses using address mask function
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Timeout function

Functional Descriptions

Two-Wire Serial Interface

The I 2 C module has two external lines, the serial data SDA and serial clock SCL lines, to carry
information between the interconnected devices connected to the bus. The SCL and SDA lines are
both bidirectional and must be connected to a pull-high resistor. When the I
idle state, both pins are at a high level to perform the required wired-AND function for multiple
connected devices.

START and STOP Conditions

A master device can initialize a transfer by sending a START signal and terminate the transfer with
a STOP signal. A START signal is usually referred to as the "S" bit, which is defined as a High to
Low transition on the SDA line while the SCL line is high. A STOP signal is usually referred to as
the "P" bit, which is defined as a Low to High transition on the SDA line while SCL is high.
A repeated START signal, which is denoted as the "Sr" bit, is functionally identical to the normal
START condition. A repeated START signal allows the I
slave device or with the same device but in a different transfer direction without releasing the I
bus control.
Rev. 1.00
2 C interface to communicate with another
392 of 486
2 C bus is in the free or
2 C
July 31, 2018