C

The U.S. District Court of Delaware's "Default Standard for Access to Source Code" follows many but not all recommended best practices for source code discovery.  This month we consider potential areas for improvement in the default rules of this important venue for patent infringement and software copyright litigation.

An introduction to embedded control systems along with a practical example on the differences between open and closed loop systems.

This webinar examines best practices for assigning fixed priorities to a set of real-time operating systems (RTOS) tasks and interrupt service routines (ISRs). Viewers will learn how and why to use optimal methods to allow a critical set of tasks and interrupt service routines to meet all of their deadlines – even during transient overload periods. Lessons learned can be applied to the development of any priority-based preemptive RTOS, including real-time Linux.

C++ compilers are available for most modern embedded processors, yet the adoption rate remains low. Here we provide very practical advice to help you can get started with C++ immediately. The discussion moves quickly from dispelling common C++ myths and identifying key C++ benefits to a set of practical tips and tricks to help you put C++ to the most effective use in your "first month" and "first year."

Too often engineers give up trying to discover the cause of infrequent anomalies--because they can't be easily reproduced in the lab--dismissing them as "user errors" or "glitches." Yet these ghosts in the machine live on. So here's a guide to the most frequent root causes of difficult-to-reproduce firmware bugs.

Too often engineers give up trying to discover the cause of infrequent anomalies--because they can't be easily reproduced in the lab--dismissing them as "user errors" or "glitches." Yet these ghosts in the machine live on. So here's a guide to the most frequent root causes of difficult-to-reproduce firmware bugs.

Whether you're using only static memory, a simple stack, or dynamic allocation on a heap, you have to proceed cautiously. Embedded programmers can't afford to ignore the risks inherent in memory utilization.

Understanding software and hardware bugs in other embedded systems can help you identify, diagnose, and fix bugs in your own.

State machines are perhaps the most effective method for developing robust event-driven code for embedded systems.

The formalism of Hierarchical State Machines (aka statecharts) makes the state machine approach truly applicable to real-life embedded systems.

What is the Design by Contract programming philosophy, what can it do for you, and why should all embedded software developers care?

A state machine is any object that behaves different based on its history and current inputs.  Many embedded systems consist of a collection of state machines at various levels of the electronics or software.

Rethinking basic programming techniques can avoid many of the problems that heap-based memory management poses for embedded real-time system designs.

The way you write software can affect the power consumption of the resulting product. Here are four approaches to minimizing power consumption through software.

A C coding standard can help keep bugs out of embedded software by leveraging common language features and development tools.

This second article on enforceable coding standards for embedded systems adds a set of additional bug-killing rules for using certain C keywords and naming global variables.

It’s a fact: When you create code, you create bugs. Listen in as we present the finer points of Test-Driven Development (TDD) - a game-changing approach to embedded software development that can greatly reduce bugs early in the development process. TDD is not a debugging technique but rather an approach to proactively preventing defects.

Many embedded systems have reliability, cost, and performance requirements that demand performance be designed into the system, from architecture to algorithms to data structures to coding guidelines.

As if debugging traditional PC/server software or even smartphone apps wasn't hard enough, debugging embedded software adds significant challenges.

A number of embedded systems, such as medical devices and printers, feature replaceable components designed to be installed new, consumed through one or more cycles of product use, and ultimately disposed.

What's the difference between a mutex and a semaphore? Misuse of these two distinct types of synchronization primitives can lead to difficult to debug defects with potentially severe consequences in safety-critical devices.

To increase security and keep bugs out of medical devices and other safety-critical embedded systems, add these 10 bug-killing rules to your embedded C coding standard.

With all the automation available today, it's easy for programmers to overlook costly overhead introduced into machine code by the compiler. Interrupt handlers are one key area worthy of a closer inspection.

Every commercial RTOS employs a priority-based preemptive scheduler. This despite the fact that real-time systems vary in their requirements and real-time scheduling doesn't have to be so uniform. Multitasking and meeting deadlines is certainly not a one-size-fits-all problem.

C's offsetof() macro can be a helpful addition to your bag of tricks, including for packing data structures and describing how EEPROM data are stored.

For embedded software developers, the most significant improvements to the C programming language made in the ISO C99 standard update are in the new <stdint.h> header file. Learn the typedef names for the new fixed width integer data types, to make hardware interfacing in C easier. 

Should you integrate a GUI into an embedded system by adding a dedicated processor or upgrading the existing one? Here are some options and trade-offs.

Finite impulse response (FIR) filters are the most popular type of filters implemented in software. This introduction will help you understand them both on a theoretical and a practical level.

The limitations of an 8-bit microcontroller (MCU) can sometimes make conventional C constructs produce suboptimal code. In this article we look at common problems on the 8051 family and discuss workarounds in C.

In 1998, the UK's Motor Industry Software Reliability Association established a set of 127 guidelines for the use of C in safety-critical systems. Here's a look at the rules, what they mean, and how they can work for you.

Language specifications, including those for C and C++, are often loosely written. A static analysis tool called lint can help you find dangerous and non-portable constructs in your code before your compiler turns them into run-time bugs.

Memory leaks can be particularly risky for long-running embedded systems. Here are some tools to identify, track, and analyze memory leaks in embedded C and C++ programs.

Some human languages are read and written from left to right; others from right to left. A similar issue arises in the field of computers, involving the representation of numbers.

The proper use of C's volatile keyword is poorly understood by many programmers. This article will teach you the proper way to do it.

The format of non-volatile data may change with a new version of software. Carefully planning data layouts and using data version numbers can make these upgrades easier.

Embedded systems programmers often value the assert() macro. This article explores the underlying definition of this handy macro, to show you how to roll your own.

The assert() macro is one of those simple tools that would not seem to merit an entire article, but I have come across an alarming number of engineers who have not heard of it or do not use it.

Products destined for use in multiple countries often require user interfaces that support several human languages. Sloppy string management in your programs could result in unintelligible babble.

The Internet Protocol (IP) is the glue that holds an internet together. Here's a compact implementation of the IP layer for embedded C programmers.

If ever there was a piece of embedded software ripe for reuse it's the memory test. This article shows how to test for the most common memory problems with a set of three efficient, portable, public-domain memory test functions.

Embedded software developers operate in a perfect digital environment but must interact with the imperfect analog real world. To do this it's essential to know how to perform calibration of inputs and sensors.

If your embedded system is on a network, the key question is not will you include TCP/IP but which subset of the Internet Protocol suite will be supported in your product.

Given a particular programming problem, what language should you use to realize the solution? Your choice could very well affect the success or failure of the project. So you'd better choose wisely.

CRCs are among the best checksums available to detect and/or correct errors in communications transmissions. This article shows how to implement an efficient CRC in C or C++.

One of the least used but potentially most useful features of the C preprocessor is the ANSI-specified #error directive. Here's a look at a couple of clever uses for #error that have proven invaluable in embedded software development.

Quite a few embedded systems include multiple processors. Sometimes these processors stand in isolation, but more often they're required to communicate over a multidrop bus such as EIA RS-485 or RS-422.

Let's face it, there's nothing sexy about the topic of cross compilers. Embedded programmers couldn't get the job done without one, but spend very little time thinking about how they work or how they could make our work easier.

Jump tables, also called branch tables, are an efficient means of handling similar events in software. Here's a look at the use of arrays of function pointers in C/C++ as jump tables.

The 8051, 68HC11, and Microchip PIC are popular microcontrollers, but they aren't necessarily easy to program. This article shows how the use of ANSI C and compiler-specific constructs can help generate tighter code.