用DSP主机端口实现虚拟I2C总线主控器

针对TMS320C54x系列DSP(Digital Signal Processor)的I/O资源缺乏问题,通过配置主机接口(HPI:Host Port Interface)或多通道缓冲串行口(McBSP:Multichannel Buffered Serial Port)作为通用I/O引脚,模拟I2C总线的时钟线SCL(Serial Clock)和数据线SDA(Serial Data);采用软件模块实现虚拟外设等方法,完成了I2C总线主控器功能.给出了以该系列DSP作为I2C总线的主控器与I2C总线从控器的无缝连接方法.结合视频应用实例,叙述了由TMS320VC5409配置具有I2C总线接口的视频处理器SAA7111A的具体过程.结果表明,利用DSP的HPI接口实现片上虚拟I2C总线主控器,是可行的、经济的.

Realization of virtual I2C master based on host port interfaCes in DSP

TMS320C54x family provides very few I/O pins, through configuration of the host port interfaces (HPI) or multichannel buffered serial port (McBSP) as general purpose I/O pins, the simulations for serial data (SDA) and serial clock (SCL) signal lines in I~2C\--bus can be realized. By taking virtual peripheral concept, a master for I~2C\--bus can also be implemented. A direct communication method with I~2C\--bus devices using TMS320C54x family chips is obtained. An example for a video application is given in order to explain how the process of the configuration for video processor SAA7111A by TMS320VC5409 is completed.This result shows that the virtual realization of I~2C\--bus master based on the HPI in 54x family DSP is valid and ecomonical.