Embedded Systems Prelim 2

Processor Technology

The architecture of the computation engine used to implement a system's desired functionality.

General-purpose processor (Microprocessor)

It is a programmable device used in a variety of applications. It has program memory and general datapath with a large register file and ALU.

Single-purpose processor (Coprocessor)

It is a digital circuit designed to execute exactly one program. It contains only the components needed to run a single program and has no memory.

Application-specific processors

 It is a programmable processor optimized for a particular class of applications having common characteristics. It is a compromise between general-purpose and single- purpose processors. It has program memory, optimized datapath, and special functional units.

IC technology

How a digital (gate-level) implementation is mapped onto an IC. It differs in its customization to a design consisting of numerous layers.

Full-custom/VLSI (Very Large-Scale Integration)

All layers are optimized for an embedded system's particular digital implementation. It has both placing & sizing transistors and routing wires.

Semi-custom ASIC (Gate Array and Standard Cell)

Lower layers are fully or partially built. Designers are left with the routing of wires and maybe placing some blocks

PLD (Programmable Logic Device)

Lower layers are fully or partially built. Designers are left with the routing of wires and maybe placing some blocks.

Design technology

The manner that converts the concept of desired system functionality into implementation.

Compilation/Synthesis

It automates the exploration and insertion of implemented details for levels.

Libraries

It incorporates pre-designed implementation from lower abstraction into a higher level.

Test/Verification

It ensures correct functionality at each level, thus reducing costly iterations.

Modeling

Process of gaining a deeper understanding of a system through imitation.

Design

Structured creation of artifacts. It specifies how a system does what it does.

Analysis

Process of gaining a deeper understanding of a system through dissection. It specifies why a system does what it does (or fails to do what a model says it should).

Synthesis

Process of generating the description of a system in terms of related lower-level components from some high-level description of the expected behavior.

Simulation

Complements analysis. Simulators can analyze circuits, particularly nonlinear circuits, much more accurately than we can do by hand.

Prototyping

Helps us ensure that the boundaries between the computer and the circuits are properly designed.

Bottom-up methodology

It is based on creating parts of a product before assembling the whole creation. This methodology starts from small components until large systems.

Top-down methodology

The system-level synthesis produces a structure of the system where each component has defined parameters and metrics. This methodology starts from the abstract up to the most detailed description.

Meet-in-the-middle methodology

Its goal is to eliminate the drawbacks and efficiently use the benefits of two previous methods.

NRE cost (Non-Recurring Engineering cost)

It is the one-time monetary cost of designing the system.

Size

It is the physical space required by the system.

Performance

It is the execution time or throughput of the system.

Power

It is the amount of energy consumed by the system. It involves power consumption.

Flexibility

It is the ability to change the functionality of the system without incurring high NRE costs.

Maintainability

It is the ability to modify the system after its initial release.

Operating Environment

It can consist of the following variables:

• Heat, Vibration, Shock, Power Fluctuations, RF Interference, Lightning, Water, Corrosion, Tampering, and many others.

Low Cost

A sophisticated processor can increase the cost of the system.

Low Energy Consumption

Many embedded systems operate on batteries.

Limited Memory

Typically constrained to a finite and small amount of storage space.

Real-Time Response

 Systems are used for controlling equipment generating response within the specified time.

Compiler

A computer program (or a set of programs) that transforms the source code written in a programming language (the source language) into another computer language (normally binary format).

Cross-Compiler

If the compiled program can run on a computer having a different CPU or operating system than the computer on which the compiler collected the program, then that compiler is known as a cross- compiler.

Decompiler

A program that can translate a program from a low-level language to a high-level language.

Language Converter

A program that translates programs written in different high-level languages is normally called a language translator, source to source translator, or language converter.

Assemblers

A program that takes basic computer instructions (called assembly language) and converts them into a pattern of bits that the computer's processor can use to perform its basic operations.

Debugger

This is a critical tool for testing. It goes through the code and eliminates bugs and errors, notifying places where they occur.

Simulators

 Code is tested for the MCU / system by simulating it on the host computer used for code development. Simulators try to model the behavior of the complete microcontroller in software.

Emulator

It is a replication of the target system with identical functionality and components.

Integrated Development Environment (IDE)

Contains the embedded software development tools needed to create your embedded software.

Data flow modeling

Process of identifying, modeling, and documenting how data moves around an information system.

Data flow program

Specified by a directed graph where the nodes (vertices), called actors, represent computations and the arcs represent communication channels.

Computation Models

It describes the mechanism assumed for performing computations and distinguishes the calculations performed in the components and communication.

Components

These include procedures, processes, functions, finite state machines, and other peripherals.

Communication protocols

These protocols describe methods for communication between components.

Shared memory

It refers to the access to shared memory unless it is restricted.

Message passing

It can be implemented easily even if no common memory is available.

Asynchronous message passing (non-blocking communication)

The components communicate by sending messages through channels that buffer the messages.

Synchronous message passing (blocking communication)

The available components communicate atomically. The component reaching the point of contact first must wait until the partner has also got its point of communication.

Extended rendezvous invocation (remote invocation)

The sender can continue only after an acknowledgment has been received from the recipient. The recipient does not have to send this acknowledgment immediately after receiving the message but can do some preliminary checking before actually sending the acknowledgment.