The Design And Implementation Of Connected Standby In Ultrabook BIOS

In the last decade,Personal Computer has begun to be on the road of innovation with the popularity of smart phones,and ultrabook was born in such case which aims to provide low energy consumption,high efficient mobile life for users.After a time,Microsoft proposed the Connected Standby concept,it is a new low power management mode supported by windows: S0 low power idle mode,that menas the system is in a low power idle state in S0 state and keeps interenet updating at the same time.If supported Connected Standby on ultrabook,the system can keep the light and thin body,meantime have the advantage of faster wake up of time,longer battery life.However,to implement Connected Standby feature on ultrabook,it requires the system BIOS,chipsets,low power components,devices and drivers tightly integration.So system BIOS plays a very important and indispensable role for implementing the Connected Standby feature,it is response to initiate chipset and devices,implement low power management for devices,and provide system information and ACPI interface for operating system etc.First,this thesis studies the working principle of Connected Standby and device power management on laptop computer.Next,it systematically analyzes and designs how to implemant Connected Standby feature on ultrabook,it includes hardware device selection and analyzation,power gating design for peripheral devices and BIOS design.Then,it implements Runtime to D3 state for ultrabook's peripheral devices and controllers,and it also implements S0 low power idle mode supporting for Intel CPU.Finnally,it has Conncected Standby platform validation test in Ultrabook engineer sample machine based on Intel Broadwell-Y SoC,the result proves the basic function implementation of Conncected Standby is correct and effective.The system power consumption is 228.5mw in S0 low power idle mode,compared with S3,the system power consumption decreases by 54% and the system batter life increases by 4 days.So implementing Connected Standby on ultrabook,it can keep system in S0 low power state,help to further extend the batter life,and provide a better user experience for end user.