System-level Architectur Modeling for Power Aware Computing Dexin Li

Background X2000 Avionics system requirement Digital Elcetronics Power- 10 times decrease Analog Elcetronics Power - 2 times decrease Computer performance - 10 to 20 times increase Design space exploration power metrics power optimization at all levels system level modeling and optimization Architectural model and behavior model

Motivation Application-driven for system level modeling Amdals law complicated system behaviors design space exploration including power metrics Current techniques make it possible COTS availability a lot of state-of-art power management techniques Clock gating bus segmentation...

What is Architectural Modeling For? Answer questions from behavior model What are the working modes a bus controller can be working on? What are the component parameters used for task scheduling? What are the possible bus topologies for a certain working mode?... Provide a platform for design space exploration parameterized/synthesizable/simulatable component library bus model system interconnect model power metrics and architectural constraints

COTS Component Components would be used for architecture composition component instantiation component encapsulation answer higher level questions parameter used in high level architecture working modes for behavioral model Component properties: parameterized synthesizalbe simulatable

Bus Model Definition I Bus-centric architecture interconnection of different buses Firewire PCI I2C,... Multi-tier bus interconnection Lower power buses Reconfigurable buses statically/dynamically optimizable bus topology

Bus Model Definition II Lower power bus techniques Serialization Bus encoding Bus segmentation Power aware bus techniques Topology reconfiguration find optimal topology offline statically find optimal topology at runtime statically computation, dynamically selection Working modes scheduling need behavioral model support

Bus Model Characterization Bus parameters: speed, width, length Bus coding methodology Bus topology Bus communication modes Bus arbitration modes Bus reconfigurability and reconfiguration cost Fault-tolerant/self-healing property Power modes and power management property Bus control type: central vs. distributed Bus partition/segmentation property

System Hierarchy I Component encapsulation To be encapsulated sub-component parameters sub-component interfaces sub bus topologies Encapsulated new parameters new bus/component interfaces new working modes

System Hierarchy II Architecture simulation model Working at various granularities Hierarchical model Input components bus model interconnection information constraints Output event trace mapping into power numbers

Example: X2000 architecture I CTOS component Bus controller (Firewire, I2C, PCI, RS422,...) Microprocessor ( PPC 750, 603e,...) Mass Memory (SRAM, DRAM, Flash) DSP sensors, camera Movement driver, pyro driver RF communication parts Bus model Firewire bus model PCI bus model I2C bus model

Example: X2000 architecture II System interconnection multi-tier bus connection (2-tiers or 3-tiers) reconfigurable bus architecture (firewire bus) bus-segmentation bus interconnection (bus bridge) Simulation model Firewire bus simulation reconfiguration process simulation communication process simulation arbitration process simulation