CPE109-4 : IMPLEMENTATION STRATEGIES FOR COMPLEX EMBEDDED SYSTEMS

For other concepts, refer to the PPT.

1. specific task

2. function

A key characteristic of all embedded systems is that they are designed to perform a _____ or _____.

1. standalone device

2. networked cars

3. networked embedded elements

Embedded system can range from a simple _______ to a chassis of _____ cards to a systems composed of many separate ______.

• Design the hardware components

• Design the software components

• Bring the two together

• Spend time testing and debugging the system.

The traditional design approach has ben to traverse the two sides of the accompanying diagram separately. That is:

• the design

• development

• test of the physical system architecture

• packaging printed circuit boards and the individual components.

The Hardware Portion of the life cycle involves:

Software Portion

Entails the tasks or algorithmic portion of the application. Such software may be written in a high-level language, assembler, or a mixture of the two.

1. microprocessor architecture

2. register structure

Work in assembly requires detailed knowledge of the _____ and its _____.

• Requirements Definition.

• System Specification.

• Functional Design.

• Architectural Design.

• Prototyping

Good system designers and designs proceed using minimum of five steps:

Identifying the Requirements

The goal of this is to capture a formal description of the complete system from the customer’s point of view and then to document these needs as written definitions and descriptions.

• Name and Description of the Entity

• Responsibilities—Activities

• Relationships

• Safety and Reliability

How to identify the requirements of the environment?

• System Inputs and Outputs

• Responsibilities—Activities

• Safety and Reliability

How to identify the requirements of the system?

Specification / System Specifications

Is a precise description of the system that meets stated requirements.

• Complete

• Consistent

• Comprehensible

• Traceable to the requirements

• Unambiguous

• Modifiable

• Able to be written

Ideally, a specification document should be?

Functional Decomposition / Functional Design

Is carried out based on a search of essential internal variables and events in the system.

1. elementary

2. leaf

The design process then consists of successive refinements or decompositions for each function (using exactly the same process) until _____ or ___ functions are obtained.

Architectural Design

The goal is to select the most appropriate solution to the original problems based on exploration of a variety of architectures and the choice of the best-suited hardware/software partitioning and allocation of functionality.

• Implementation (or factory) cost

• Development time and cost

• Performance and dependability constraints

• Power consumption

• Size

In hardware architecture, among the important criteria that we strive to optimize are:

Clock speed

An important consideration of choosing a CPU is the range of an embedded microprocessor system is from the low hundred of megahertz (200 MHz) to over 1 GHz.

Single Instructions, Multiple Data (SIMD)

Processors also offer instructions that are ____ to optimize the execution of algorithms that exhibit data-level parallelism.

Symmetric multithreading

With the addition of a relatively small amount of logic, the processor presents two separate logical cores

Integration levels

As this increase, more and more logic is added to the processor die, creating families of application-specific service processors.

System on chip (SOC)

Is a term often used to describe these highly integrated processors. It integrates capabilities to external memory devices and nonvolatile storage using glue-less interfaces.

Glue-less

A term used to indicate that there is no additional logic needed to connect the two devices.

Power Consumption

It is often beneficial for an embedded application to group work into bursts of activity with the processor running at full clock rate followed by periods of processor idle states.

Form Factor

In many cases, considerable effort is expended in designing a core compute module that can be employed in a number of different product lines with varying I/O or interface capabilities.

Expansion

An attribute often sacrificed in designing embedded systems is the ability to expand hardware capabilities over time. Given that the platform has a specific purpose, the designer has the ability to dimension the platform for the specific usage

Application-Specific Integrated Circuit (ASIC).

Add capabilities by adding a FPGA or by developing an ____.

• Multilevel secure (MLS)

• Safety Integrity Level (SIL)

• Federal Information Processing Standards Publications (FIPs)

There are many safety and security standards that may be applicable to the industry you work in, such as:

Reliability/Availability

It is important to validate and test your system by running your system for several days and reviewing such resources. It’s not a good idea to assume your system will be restarted regularly.

Error-Correcting-Code (ECC) memory

Automatically corrects single bit errors and detects multiple bit errors in memory.

Connectivity

The embedded platforms must support the latest IP stacks. Finally, a transition to IPv6 is likely.

Ethernet

The ubiquitous wired interface available on many platforms.

1. 802.11

2. Wi-Fi

3. Zigbee

For wireless interfaces, _____ and ______ are the most prevalent. Other wireless technologies such as Bluetooth and those based on IEEE 802.15.4 such as ____ are provided, depending on the application.

Security

It is critical that embedded devices have an active life cycle, where security-related updates are pushed to the devices just as they are in the desktop environment.

• Detailed design

• Debugging

• Validation

• Testing

A prototype implementation includes: