基于异步FIFO的Camera Link数字图像光纤传输技术

Fiber Optical Transmission of Camera Link Digital Video Image Based on Asynchronous FIFO

为满足数字图像的远距离传输需求,设计用于传输Camera Link接口数字图像的光纤通讯系统。系统分为发送和接收两个部分,分别负责Camera Link数字图像到光信号的转化以及相应的逆变换过程。采用Cyclone I EP1C12 FPGA作为发送和接收板卡的逻辑控制核心。在发送板卡的FPGA内设计逻辑控制模块,操纵两个异步FIFO(先入先出队列),将接收到的数字图像缓存,用本地时钟读取后再进行串行化转换。在不改变数字图像时序关系的前提下,用本地时钟替换原有的像素时钟,消除像素时钟不稳定性对后续传输影响。实验表明,利用该技术可以有效提升光纤传输系统的适应性、稳定性,改善、消除由像素时钟抖动造成的传输图像抖动现象。

A Camera Link digital video image transmission system based on digital fiber optical communication was designed in order to meet the long distance transmission demand.The transmission system consisted of two parts,the sender part transfered the digital image data into optical signal and the receiver part did the inverse transformation.Cyclone I EP1C12 FPGA was used as the logical central control unit.A ping-pong operation control logic was designed in the sender part,controlling two asynchronous FIFO to buffer the digital image data from the camera.Serialization processed after logical clock read the image data out.So that local clock on board replaced the pixel clock along with the digital image data,under the precondition that the sequence of the digital image data remain the same.Experiments show that this method can improve the adaptability and stability of the transmission system,eliminating the image flicker caused by clock jitter.