Design And Implementation Of MAC Software Of High-speed WLAN Chip

Through the realization of 802.11 protocol family,Wi-Fi has occupied the absolute dominant position in the high-speed WLAN.MAC layer is an important layer in Wi-Fi communication.On the basic of reliability and real-time provided by MAC hardware and considering the requirements of 802.11 MAC standard,MAC software can provide the flexibility of development and ease of upgrade,and the combination of hardware and software can effectively improve system throughput.Currently a variety of WLAN equipment spring up on the market,but the WLAN chip manufacturers are few,because most of the market is still dominated by foreign manufacturers.The development of domestic WLAN chip is very limited,as the core part of control WLAN,MAC software chip is very important and worth to explore.However,due to the close integration of MAC software design and WLAN chip hardware design,there are few suiable for realizing the high-rate MAC software to refer.MAC software like "intersection" and hardware like"street",even if "the road" is more wider,it can not get away from the limits by the MAC software design and implementation on performance of this " wide road".This actual is completed on the basic of the project of an enterprise WLAN chip developed.The project in line with the purpose of independent innovation,aims to design in accordance with 802.11 and affiliate agreement industrial-grade communications chips.According to the design purpose,MAC software need to implement device configuration,data transmation and receiption,management of state and parameter,etc.Based on the familiar with the protocol family related 802.11 MAC layer,according to protocol requirements for realization to part MAC layer software and hardware,and clear the actual design requirements of MAC software.By abstracting MAC software features,this paper presents a set of effective MAC software system architecture-encapsulated the input of MAC layer into different events,and the handler functions to be the library,by processing the event generated from interface and system internal,complete data flow transmission and device management control.Furthermore,this paper divides the MAC software system architecture into event manager,event analyzer,MAC library,Host interface and hardware interface.Event manager manage input generated from the Host interface,the hardware interface or MAC library as events to classify.Event analyzer extract the event sequentially to analysis by event manager,and send the output to Host interfaces,hardware interfaces,or call the MAC library functions for further processing according to the requirements.In addition,in the realization of MAC library,MAC software decide the processing by the current state of the system and the input type and return users results of opertation reference to the principles of the hardware state machine,so by using this mechanism WLAN system skillfully realized management control from DISABLE status never connected to the ENABLE state connected.Because the chip is taped out stage,this article uses the FPGA has set up a platform hardware emulation.First,the configuration of equipment using the application or send data to the device,by WireShark caught tools caught on in the process of test data and parsing.Finally,through the different layers in the MAC hardware loopback test to verify the MAC software the correctness of the data transmission process.Verification results show that the correct MAC software to achieve the equipment configuration,data transceiver and equipment condition and parameters of the management and other business functions,in line with the MAC software design requirements.