AN554

M Author: AN554 In most systems the microcontroller is the master and the external peripheral devices are slaves. In these cases this application note can be used to attach I2C slaves to the PIC16CXXX (the master) microcontroller. The multi-master system is not implemented because it is extremely difficult to meet all the I2C Bus timing specifications using software. For a true slave or multi-master system, some interface hardware is necessary (like START & STOP bit detection). In addition to the low level single master I2C routines, a collection of high level routines with various message structures is given. These high level macros/routines can be used as canned routines to interface to most I2C slave devices. As an example, the test program talks to two Serial EEPROMs (Microchip’s 24LC04 and 24LC01). Software Implementation of I2C™ Bus Master Amar Palacherla Microchip Technology Inc. INTRODUCTION www.DataSheet4U.com This application note describes the software implementation of I2C interface routines for the PIC16CXXX family of devices. Only the master mode of I2C interface is implemented in this application note. This implementation is for a single master communication to multiple slave I2C devices. Some PIC16CXXX devices, such as the PIC16C64 and PIC16C74, have on-chip hardware which implements the I2C slave interface, while other PIC16CXXX devices, such as the PIC16C71 and PIC16C84, do not have the same on-chip hardware. This application note does not describe the I2C...