I2C Controller Reference Design

The use of this design is governed by, and subject to, the terms and conditions of the Intel® Design Example License Agreement


The Microtronix inter-IC (I2C) Controller reference design uses the I2C controller intellectual property (IP) along with the Nios® II embedded processor and peripherals. This reference design is built to work on the Nios II development kits specified below.

The I2C bus is a simple two-wire, bidirectional interface developed for I2C communication with Santa Cruz headers and any I2C slave device with compatible pins. This flexible design makes it easy to communicate effectively with the Microtronix I2C board.

The Microtronix I2C IP core is a complete I2C solution offering three modes of operation: I2C master controller, I2C slave controller, and an 8-bit parallel I/O (PIO) slave device. Three I2C bus transmission speeds are supported: 100 Kbps (normal), 400 Kbps (fast), and 3.4 Mbps (high speed). The Microtronix I2C master/slave core provides a generic memory-mapped bus interface. It is also designed as an SOPC Builder ready component and integrates easily into any SOPC Builder generated system using a Nios II Avalon® system interconnect fabric.

The Microtronix I2C PIO slave core is provided as an Intel Quartus® software Intel FPGA IP and integrated into the parameter editor.


  • I2C master/slave transmitter and receiver IP core
  • Nios II embedded processor
  • I2C 8-bit PIO slave core
  • Own address and general call address detection
  • Input clock filter
  • Meets Philips I2C bus specification version 2.1
  • Seven bits addressing format
  • Single byte transmit and receive buffer
  • 300 logic elements (LEs) for Avalon master/slave, 100 LEs for PIO
Figure 1 - Microtronix I2C Controller Reference Design

Request this reference design along with an evaluation version of the I2C PIO IP Core. 

Reference Designs Disclaimer

These reference design illustrations remain the copyrighted property of Intel or its licensors and may be used within Intel Corporation devices only. They are being provided on an "as-is" basis and as an accommodation, and therefore all warranties, representations, or guarantees of any kind (whether express, implied, or statutory) including, without limitation, warranties of merchantability, non-infringement, or fitness for a particular purpose, are specifically disclaimed. Intel expressly does not recommend, suggest, or require that these examples be used in combination with any other product not provided by Intel.