The Research And Implementation Of Embedded TCP/IP Stack Based On F28M35HX

With the rapid development of information technology，the Industrial Ethernet isbecoming the main trend of industrial control network.The remarkable progress ofembedded technology,also makes it easier to improve the real-time and reliability ofethernet communication.Based on the discussion of present situation and developmenttrend of Industrial Ethernet,we realize the importance of real-time and reliablecommunication of Industrial Ethernet. Focusing on this situation,this thesis proposes asolution of embedded TCP/IP stack from hardware implementation to softwareimplementation.In the implementation of hardware,this thesis chooses the Concerto F28M35HxMicrocontroller as the hardware core.F28M35Hx has a dual-core structure.The Cortex-M3core provides plentiful communication modules,and at the same time the TMS320C28xprovides powerful calculation ability.This thesis develops the network module ofF28M35Hx——EMAC,and also designs its peripheral circuit.In the implementation ofsoftware,the thesis designs the method of transplanting Real-time Operating System——μC/OS-Ⅱ and lightweight TCP/IP stack——LwIP,and also shows the details of thetransplant process.μC/OS-Ⅱ is a preemptive real-time efficient kernel which supportsmultitasks,and it can be transplanted easily. Since the μC/OS-Ⅱ does not contain thenetwork protocols stack,we choose transplanting LwIP to make up for the networkmodule.The thesis analyzes LwIP’s protocol modules,process model,interfacesmanagement and memory’s allocation in depth.Besides,it also programs operating systememulation layer functions and underlying network device drivers of LwIP.In order to test the communication of transplanted LwIP,a tiny Web server isembedded in the application layer.Later, the Modbus/TCP is transplanted in applicationlayer.Then the thesis chooses a HMI with network interface as Client while regards theF28M35Hx with Modbus/TCP protocol as Server,and applies the Client/Server model to a closed-loop control system of auto-retractable cord.In this test experiment,there will beplentiful exchanges of information,and these exchanges will test the designed solution’sconformance.Both of the two test experiments indicate that it is right to transplant μC/OS-Ⅱ andLwIP.The solution with combining μC/OS-Ⅱ and LwIP do provide real-time and reliablenerwork,and can expand into industrial applications.