Software Implementation Of 40Gbit/s QSFP Optical Transceiver Module

In recent years, the rapid development of Internet has put forward higher and higher request to the communication system, and optical transceiver module developed rapidly with development of optical fiber communication system. 40Gbit/s QSFP optical transceiver module mainly locate in the physical medium dependent layer of Optical Fiber Communication Ethernet Protocol, it is a nuclear part of the electro-optic and optic-electro conversion. In order to comply with the need of intelligent optical networks, the development of optical transceiver module will be more intelligent and miniature, it helps the network management unit quickly locket the fault, thus simplify maintenance.Under the above background, this paper make a research on the 40Gbit/s QSFP optical transceiver module with digital diagnostic monitor function. This paper analyses the design principle and the function of every part, discusses SFF-8436 protocol in detail, according to which, the paper complete the program of digital diagnostic monitor function. To make full use of the MCU of the optical transceiver module, the paper provide solutions to simulate the function of the EEPROM with the MCU. In the end, the paper offer the test result of the optical transceiver module and make a study of temperature compensation.In the program, the first step is to initialize the optical transceiver module, then complete digital diagnostic monitor function in the timer interruption, and communicate with upper computer in the I2 C interruption. The initialization of the optical transceiver module mainly configure the two driver chips with the I2 C communication protocol, configure ADC to prepare for data acquisition. Digital diagnostic monitor function is to use ADC to collect the data of VCC, temperature, bias current and received optical power, then compare the data with threshold and update the result in the EEPROM. In addition, dealing with the alarm is also necessary. Digital diagnostic monitor function is implemented every 50 ms in the timer interruption. The normal optical transceiver module will storage the data in a real EEPROM, to make full use of the resource of the MCU, this paper provide a solution to simulate the function of the EEPROM with the MCU, thus take the method of communicating with upper computer in the I2 C interruption. From the use of the effect of view, the simulated EEPROM is equal to a real EEPROM.Finally, in order to test the optical transceiver module, the testing program and several parameters are given by the author. Through a large number of tests, performance of the optical transceiver module meet the requirement of IEEE Std 802.3baTM-2010 protocol. In the end, to improve the performance of the optical transceiver module, the author put forward a plan of temperature compensation and provide the specific data.