With Ddm Function Of 4.25gbps Optical Transceiver Module Design And Research

The study based on 4.25Gbps Fiber Channel Multimode SFP Transceiver which isthe significant project of Shenzhen Photon Technology Co. Ltd is proposed in this thesis.The principle, purpose and design scheme of every structure of SFP are introduced. Thetotal design scheme including the hardware circuit scheme, the code for MCU, thecommunication interface, the IIC communication functions and the testing software arealso given after analyzing the overseas technical development and the existing technicalconditions of the company. A series of testing scheme are given for testing the SFPmodule at the last part.The digital diagnostic monitoring is achieved by using a MCU which also providesthe IIC interface in the hardware scheme of this thesis. The analog signals which arecollected from the LD and ROSA are converted to digital signals which are stored in thespecial area of the Flash according to SFF-8472. After configuring the I/O ports andprogramming the MCU, the DDM is succeeded. The IIC interface is also provided forthe module after programming the MCU. For improving the time and storage efficiencyfor the MCU program, some optimization ways are given.The IIC communication functions are needed while communicating between SFPand computer. The IIC communication functions including single/multi-byte read/writefunctions based on parallel port are designed in the form of dynamic-link library usingVC++6.0. It is testified to be high-dependable and high-speed. The dynamic-link libraryis called by the testing software designed using VB to improve the characteristics of SFP.The alarms of TxFault and RxLos are provided in the software by judging the status ofspecial parallel port pins. The services of enabling or disabling transmitter and rateselecting are also provided in the software.A series of testing schemes for some important parameters of SFP are given at thelast part of this thesis. After times testing, the parameters such as OMA, eye-diagramand receive sensitivity of the SFP module employing the scheme of this thesis areexceeding the overseas same products. It is coincident with the design target.