基于虚拟I^2C总线的多并行口扩展技术

The Technique of Extending Multi-Parallel Ports Based on I^2 C-Bus

对于已经定型的产品,为适应新的要求,设计者往往会重新进行设计,极大浪费了时间,增加了开发成本。文章提出并详细介绍仅用不带I2C总线的单片机的两个引脚,借助于PCF8574,通过虚拟I2C总线来扩展多个并行口,以低廉的代价升级产品性能的方法。

In order to meet the ne w demands for the finalized designed product,designers often redesign their pro duct.Itwastes a great deal of time and adds developed cost.It is put forward a nd introduced the method of extending multi-parallel ports to update the produc t with low cost using a single chip microcomputer with no I2C-bus and two pins ,by use of PCF8574,through virtual I2C-bus in this paper.