一种基于自定义以太网帧的高速数据传输协议及在成像系统中的应用*

针对将TCP/IP协议栈运用在嵌入式成像系统中作为通信方式时所存在的传输速度较低的不足，提出一种将数据封装在自定义以太网帧中进行传输的通信方式，并针对这种方式实现了网卡的驱动，定义了3种帧格式它们分别用于启动曝光、数据传输、数据重传等，设计一种基于状态机的控制协议实现相机的控制及图像数据的传输，最终在硬件平台上实现基于这种方法的成像系统。实验测试表明在NiosII嵌入式处理器工作在150MHz、uCosII操作系统条件下，基于自定义以太网帧的传输方式能将图像数据的传输速率提升4倍以上，这种方式特别适用于传输速率要求较高且资源有限的嵌入式程序成像系统。

High-speed data transfer protocol based on custom Ethernet frame and its application in imaging system

For disadvantage of lower transmission speed which exist in embedded imaging system using TCP/IP protocol stack, this paper proposed a new communication method which package the image data in custom Ethernet frame for transmission. This paper defined 3 kinds of frames which are used to start the exposure, data transmission, data retransmission, and designed a control method based on state machine for camera control and image data transmission. To achieve this method on the hardware platform which using the NiosII embedded processor, test the network communication speed and make it compare with the speed of the system based on TCP/IP protocol stack, found that the increase of the speed is more than 4 times. This communication method is particularly suitable for the embedded imaging system which has limited hardware resources and high requirements of transmission rate.