IR Drop Analysis And Optimization Of 28nm Low-Power Mobile Baseband Chip

In recent years,with the development of mobile Internet technology, portable mobile intelligent equipments constantly updated, the performance of the mobile devices had a big improvement.Because of the increase in performance and working frequency of mobile devices, internal logic of the chip became more and more complex, power dissipation problems were more and more serious accordingly.The increase in power consumption reduced the battery life of mobile devices,low power methodology became an important aspect of the design of a chip.With the increase of the power consumption,IR Drop was caused inside the full chip,and IR Drop caused the shortage of power supply for internal logic cells,this reduced the performance and even lead to the disorder of chip function.If mobile baseband chips have serious IR Drop problems,it could directly lead to some certain features of mobile devices can not be achieved.Therefore,the IR Drop analysis of the baseband chip is a major topic which should be considered well by physical design engineer.This article is based on one 4G mobile baseband chip which designed by the author's company, the article deeply discussed static and dynamic IR Drop under 28 nm process which based on low power mobile baseband chip,designed and implemented several methods to optimize IR Drop in the physical design phase,which effectively reduced the voltage drop inside the chip.The paper firstly studied the power consumption theory of digital integrated circuit,the current low power design methodology and Unified Power Format(UPF) are also analyzed.And discussed low power network topology of SOC chip, implemented the power network of the mobile baseband chip in physical design phase. On this basis,used Apache's Redhawk simulation tool to perform the static and dynamic IR Drop analysis for 28 nm mobile baseband chip,stated the static and dynamic analysis methods and the design process in detail. Introduced the definition of input file,the definition of each parameter which was used in IR Drop analysis,introduced the process of power consumption calculation and resistance network extraction,and showed the results of IR Drop analysis in the project.This article deeply studied the causes of IR Drop problems which based on the results of the mobile baseband chip, designed and implemented several optimization methods to decrease the IR Drop value in physical design phase.By using the methods proposed in this paper,the maximum voltage drop of the mobile baseband chip decreased from 29.5247 mv to 20.77 mv,reduced by about 29.65%,effectively implemented the decrease of maximum IR Drop value inside the mobile baseband chip without impacting the chip function and timing.It could be a certain practical reference for the personnel engaged in IR Drop analysis.Finally,the paper also introduced some optimization methods for dynamic IR Drop analysis,and summarized and prospected the static/dynamic analysis and optimization.