Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 1 Hardware/Software Codesign of Embedded Systems CONCURRENT ENGINEERING Voicu Groza SITE Hall, Room ext

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 2 CONCURRENT ENGINEERING General Issues System Development Life Cycle System Categories Reactive Real-Time Embedded Systems

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 3 Motivation for Concurrent Engineering * Project size: 5 … 500 people; Time = money: –Development time versus development cost; * Average product life time was 23 years; * For mobile phones it is 6 to 12 months; * 60% of Ericsson’s profit comes from products younger than 3 years; * Late arrivers loose market share; * Phase and activity overlapping is crucial; * Communication and documentation are essential; * The development task must be partitioned into horizontal and vertical subtasks. * The development time must be shortened while - the design complexity increases and - the product quality level remains high.

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 4 Definitions and Scope * CE := Paralleling of life cycle functions + Consensus + Cooperation * CE := Minimization of total product development time * CE := Global optimization of total product live cycle (maximize quality, reduce lead time, lower cost) * CE := Integrate product and process design over the entire enterprise

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 5 Influencing Agents: the 7 Ts Teamwork Talents Tools Time Technology Techniques CE Tasks

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 6 Project Phases Project management Expression of need Project definition Planning & organization Project development Project completion Time Abstraction

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 7 Involved People * Customers - Users - Marketing and sales personnel - Operators - Maintenance personnel * Product manager * Project manager * Requirement definition engineer * Specification engineer * Designer * Implementation engineer * Test engineer

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 8 Development Phases * Requirement definition: The most informal part of a product development * Specification: The first abstract description of the product * Design: Functional partitioning and architecture selection * Implementation: Implementation of components and integration * System validation * Production: Experimentation with prototypes and final product production * Operation: Corrective, adaptive and preventive maintenance

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 9 Life Cycle Models * Waterfall model * V-cycle * Spiral model * Contractual model

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 10 The Waterfall Model Based on the assumption of document completion at the end of each stage. This is problematic for applications for which the requirements and implementation are poorly understood. Specification Design Implementation Requirements Definition Testing & Maintenance

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 11 The V- Cycle Model Requirements Definition Specification System Design Component Design Coding Unit Test System Integration System Validation Operational Test Certification Validation Specification Design & Development Test & Evaluation Operation & Maintenance NEEDPRODUCT DESIGN VALIDATION

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 12 The Spiral Model - Risk Driven Determination of objectives, alternatives and constraints Evaluate alternatives, identify & resolve risks Planning next phases Develop & Verify Life cycle plan Development plan Integration & test prototype operational prototype concept requirement SW product design Detailed design Unit test Integration & test Implementation Design validation & verification Risk analysis RA CUMULATIVE COST

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 13 Concurrency Between Process Phases * Align each step as far to the left as possible; * Maintain the precedence of tasks; * Minimize the horizontal overlap between two consecutive tasks; * Maximize the independence of tasks; Mission Definition Concept Definition Engineering & Analysis Product Design Prototyping Production Engineering &Planning Production Operations & Control Manufacturing Continuous Improvement, Support & Delivery Product Requirements Constraints Changes

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 14 Design Phase Overlap Waterfall Model Specification Design Implementation Test EFORT TIME

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 15 Design Phase Overlap Concurrent Engineering Specification Design Implementation Test EFFORT TIME

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 16 Effort Distribution Effort/time Approach with high effort on specification Approach with low effort on specification SpecificationDesignImplementation Test

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 17 Error Correction Cost SpecificationDesignImplementation Production Operation Time of Error Detection COST Log scale

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 18 Time to Market Cost Model Market rise Market fall Revenue $/mo System conceptProduction Time to market Time

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 19 Productivity Factors Productivity team ability product complexity real time constraints experience with the application high-level modeling design tools development of tools experience with tools experience with design language

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 20 Basic Principles of CE * Early problem discovery: Problems discovered early are easier to solve. * Early decision making: In the beginning the design space and the potential to find global optima is greater. * Work structuring: Humans are not good on working on multiple tasks simultaneously; they are good on systematically structuring their work and the work environment so that each task is independent. * Teamwork affinity: Cooperation between persons and teams is based on trust and positive experience. * Knowledge leveraging: Since the required knowledge is distributed, the decision making process must coordinate distributed knowledge. * Ownership: The motivation is higher if teams or persons own a problem and assume responsibility. * Consistent objectives: Persons, groups, and organizations have self interests which might not be consistent with the companies objectives.

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 21 Concurrency and Simultaneity * Parallel product * Concurrent resource scheduling * Concurrent processing * Minimize interfaces - Minimize product interfaces –To facilitate handling, maintenance, testing, and manufacturing; –To facilitate concurrent activities - Minimize process interfaces - Automate data flow * Efficient communication and efficient reviews * Design documentation and design decision documentation * Quick processing of individual activities

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 22 Partitioning of Development Tasks: Vertical Slices Specification Design Implementation IntegrationValidation

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 23 Horizontal Partitioning: Structural and Functional Slices The number of interdependent tasks must be minimized Specification Design Implementation IntegrationValidation STRUCTURAL COMPONENTS

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 24 Functional Slicing * Functional slices may or may not be implemented by structural components * Functional slicing increases the potential for concurrent activities * Functional slicing allows to start with system simulation and system validation very early. * Early system level validation generates bug reports and valuable feed back for the design of individual components.

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 25 Benefits of Concurrent Engineering * Rationalization in the manufacturing process * Working parallel * Improved communication and providing better input * Preempting errors and spotting problems early * Flexibility to accommodate changes * Decreased occurrence of obsolescence * Cross training * Better use of scarce technical resources

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 26 Pitfalls * Problem with handling of information and data flow; * Risk of wasted efforts due to parallel activities; * Error correction activities due to incomplete and immature information; * Increased development cost

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 27 System Categories * Embedded systems * Real-time systems * Distributed systems * Interactive systems * Reactive systems * Communication systems (protocol processing, switches, etc.) * Data processing systems (processing of signals, pictures, voice, etc.)

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 28 Embedded Systems Embedded electronic systems implement application specific dedicated functions in a special environment. * Dedicated systems * Environment is complex * Environment establishes various nonfunctional constraints * Environment is not completely known * Interfaces to other subsystems - Digital protocols - Analog interface - Mechanic interface - Chemical interface * Sensors and actuators

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 29 Real-time Systems Real-time systems have a well defined timing behaviour imposed upon them by the environment. * Well defined timing behaviour * Timing constraints - Local timing constraints - Input rate constraints - Output rate constraints * Several simultaneous activities - Observe events - Evaluate decisions - Generate actions * Synchronization facilities

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 30 Distributed Systems Distributed systems implement an integrated functionality at spatially separated locations. * Communication facilities and protocols - Specification. modeling, implementation, and verification of communicating systems - Synchronous and asynchronous communication - Shared memory - Shared bus - Point-to-point protocols and structures * Distributed control threads - Parallel threads - Dynamic creation and destruction of threads - Remote procedure call (synchronous and asynchronous) * High complexity

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 31 Interactive Systems Interactive systems have an intense and versatile data flow to I/O devices with soft timing constraints on performance and response time. * Complex mixed HW/SW user interface * Soft timing constraints which must be met ”on average”

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 32 Reactive Systems Reactive systems are connected to the environment via sensors and actuators and implement control and data processing functionality. * Versatile interface and communication facilities and protocols - Interfaces to mechanical and analog devices - Many nonfunctional constraints (size, power, shape, weight, etc.) * Hard timing constraints on response time * The behaviour is well modeled by a finite state machine

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 33 Communication Systems Communication systems process and connect streams of data according to protocols and switching rules. * Tight performance constraints on throughput * Moderate timing constraints on latency * Large memory requirements with irregular access pattern * Large number of internal interconnections and I/O ports * Implementation of the multi-layer protocol stack is partly in HW and partly in SW

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 34 Data Processing Systems Data processing systems transform streams of data according to complex mathematical transformations with high performance requirements. * Tight performance constraints on throughput * Varying memory requirements with regular access pattern * Only one or few data streams * Complex mathematical transformations * Implementation is partly in custom HW and partly in SW on DSPs

Voicu Groza, 2008 SITE, HARDWARE/SOFTWARE CODESIGN OF EMBEDDED SYSTEMS 35 Development Context Company Project development Resources Activities Project management Projects Company management