Study On Network Access Design Based On NIOSII

With the rapid development of Network, more and more electric equipments are needed to connect with network for implementing the long-distance control and sharing resource. The technology of embedded network systems is one of the main trends of future application. A field-programmable gate array (FPGA) is adopted for the design because of its flexible design, high speed, reconfiguration, low risk of implementation and short period of development.In this paper, a new method of embedded network access system, which is based on soft core of NIOSII, and can realize accessing Internet by wireless and wired mode, is described. A GPRS module, MC55 is used to implement the wireless Internet access, while an Ethernet controller IC, Lan91c111 is interfaced with the NIOSII for access Internet by wired. This system can be adapted to the requirements of network access in different area because of its simple structure and flexible design.This paper is composed of four parts:Firstly, the principle and the development of FPGA are expounded, as well as SOC, SOPC, NIOSII and network access.Secondly, the design of the system hardware is introduced, as well as the function of some main IC and modules.Thirdly, the method of customizing a 32-bit microcontroller is described in detail. The interfaces between the customized microcontroller with standard components are implemented. Those standard components, such as SDRAM, FLASH, PIO, are attached to the Avalon bus, as well as other customized modules.Finally, the software design method based on NIOSII and the test results of the system are presented in detail.