Hi Forum Members,

We all know I2C is a synchronous transfer bus. With maximum bit rate 100kHz [ I am talking about standard i2c not the 400kHz high speed I2C ]. And I2C does support slower bit rates than 100kHz very well. When we use a hardware I2C derivative then there is no need to worry about I2C handling and its timing.

But say if we use soft routines for I2C handling with micro being master and some other device say a PCF8574 port expander being slave mode & say I am communicating on soft I2C at 50kHz and while data transfer was on there is an interrupt which lasts for some time say 6mS interrupting I2C data transfer. Upon return from interrupt the micro will again start executing the soft I2C data transfer. In such an event will there be any problem or not? Friends I have never come across any problem due to above stuff so far but was just wondering can such a thing ever lead to problem or I2C bus immune to such timing disturbances.

Thanks to all of you for reaing my post.

Thanks & Regards,
Prahlad Purohit