lib_i2c

Summary#

I²C (Inter-Integrated Circuit) is a multi-master, multi-slave, synchronous, serial communication protocol used for communication between integrated circuits on the same board. Developed by Philips, it requires only two lines: the SDA (Serial Data Line) for data transfer and SCL (Serial Clock Line) for clock signals. I²C is popular in applications for connecting low-speed peripherals like sensors, EEPROMs, and ADCs. It supports various data rates, typically up to 3.4 Mbps in Fast Mode Plus and Ultra-Fast Mode, and allows multiple devices to share the same bus.

lib_i2c contains a software defined, industry-standard, I²C library that allows control of an I²C bus via xcore ports.

lib_i2c provides both controller (“master”) and peripheral (“slave”) functionality.

The I²C master component can be used by multiple tasks within the xcore device (each addressing the same or different peripheral devices).

The library can also be used to implement multiple I²C physical interfaces on a single xcore device simultaneously.

Features#

• I²C controller (master) and I²C peripheral (slave) modes

• Supports speed up to 400 Kb/s (I²C Fast-mode)

• Clock stretching support

• Synchronous and asynchronous APIs

Known issues#

• The library has functions that wait on SCL high, through either an event or a polling loop. If these are called on a system where the pull up isn’t present then the application can hang forever.

Development repo#

• https://github.com/xmos/lib_i2c

Required tools#

• XMOS XTC Tools: 15.3.0

Required libraries (dependencies)#

• lib_xassert (www.github.com/xmos/lib_xassert)

Related application notes#

The following application notes use this library:

• AN00156: How to use the I²C master library

• AN00157: How to use the I²C slave library

• AN00181: xcore-200 explorer accelerometer demo

Support#

This package is supported by XMOS Ltd. Issues can be raised against the software at www.xmos.com/support