Design And Research Of General Motherboard Based On Loongson 3A4000

In a long historical period before "Godson-1" broke the "coreless" situation of China's information industry,our CPU and supporting chip industry almost all depended on imports,and huge profits flowed abroad.At the same time,the widely imported CPUs and chips were used as the core components of motherboards and other electronic products,which bringing more security risks.PRISM,ZTE incident and the US ban on Huawei have repeatedly alerted us that China needs to master the truly independent and controllable technologies to compete with other countries in the world.For these reasons,designing and studying the general motherboard with "Loongson 3A4000" as the processor,which can timely serve the promotion and application of China's information technology application innovation industry,and promote the ecological industrialization development of domestic CPU and the diversified development of motherboard design.According to the functional and performance requirements of electronic substitution in domestic information technology application innovation industry for PC,and combineding with the research of "Loongson 3A4000" CPU reachable technical index,refering to the general motherboard structure of "Loongson 3A4000+7A1000",the system structure and function of motherboard is determined,and the chips of the key module are selected.In the schematic design,combineding with the requirements for the motherboard function and the performance of each interfaces,the modular design is carried out,in which the design of memory reset control and CPU power supply is optimized,and the domestic chips are used in the circuit design of the key modules such as power conversion and network interface,and the corresponding functions are realized.Before the PCB design,signal integrity,electromagnetic compatibility and other basic issues are discussed,the problems that need to be paid attention to in the design are put forward,and several solutions are given.Under the guidance of the discussion results,PCB stack design,characteristic impedance design and subsequent layout and route design are carried out in combination with interface signal features and electrical characteristics.Finally,debugging and testing the soldered motherboard,the key points of each debugging project and the debugging problems are given.The display,memory access and network performance are tested and evaluated through Stream,Netperf,Unixbench,Glxgears and IOZone standard test softwares.The debugging results and performance test results show that the motherboard design basically achieves the design goals of function and performanc.The success has a certain reference significance for PCB optimization,debugging and other design processes in motherboard design,and has a certain guiding role for subsequent motherboard mass production,product testing and other work.