应用于光模块的低成本曼彻斯特解码方案

Low cost Manchester decoding scheme for optical modules

为了降低传统光模块行业中曼彻斯特解码方案的成本并提高其兼容性和可靠性,提出了一种应用于光模块的低成本曼彻斯特解码方案。首先,利用采样电阻与运放组合电路对信号进行预处理,解决不同光强条件下采样后信号幅值过小或饱和而无法解码的问题。其次,利用控制器内部的可编程计数阵列(PCA)对信号进行边沿捕捉和持续时间计算,解决信号同步问题。在同步判断过程中,引入了持续时间容差设计,并对数据帧头的丢失进行了优化判断,从而显著提升解码方案的抗干扰能力。最后,利用控制器内部的可编程逻辑单元(CLU)和定时器提取信号时钟,并将信号发送到内部串行外设接口(SPI)模块完成解码,以提高解码效率并解决控制器的资源消耗和解码兼容性问题。测试结果表明,该方案能够进行准确且稳定的数据解码,满足实际的应用需求。

In order to reduce the cost of Manchester decoding scheme in the traditional optical module industry and improve its compatibility and reliability,a low-cost Manchester decoding scheme for optical modules is proposed.Firstly,the combined cir-cuit of sampling resistor and opamp is used to preprocess the signal to solve the problem that the sampled signal amplitude is too small or saturated under different light intensity conditions and cannot be decoded.Secondly,the programmable counting array(PCA)inside the controller is used to capture the edge and calculate the duration of the signal to solve the problem of signal syn-chronization.In the process of synchronization judgment,the duration tolerance design is introduced,and the loss of data frame header is optimized,which significantly improves the anti-interference ability of the decoding scheme.Finally,the programmable logic unit(CLU)and timer inside the controller are used to extract the signal clock,and the signal is sent to the internal serial pe-ripheral interface(SPI)module to complete the decoding,so as to improve the decoding efficiency and solve the problem of re-source consumption and decoding compatibility of the controller.The test results show that the scheme can decode data accurate-ly and stably,and meet the practical application requirements.